equatinal by elimination melha
8n-3y = 18 and5x+6y=27
Answer:
x = 3 and y= 2
Explanation:
Given equations:
8x - 3y = 18 - ---- (I)
5x + 6y = 27 -------(II)
Solve this problem by elimination;
In the elimination method, we simply find a common term that can make one of the variables in the two equation the same. Then we either add or subtract to remove the variable.
Mulitply equation (i) by 5 to give equation III
Mulitply equation (II) by 8 to give equation IV
5(8x - 3y) = 5(18) ------- III
8(5x + 6y) = 8(27) ------- IV
40x - 15y = 90------- III
40x + 48y = 216 ------- IV
Subtract equation III and IV;
-15y - 48y = 90 - 216
- 63y = -126
y = 2
Solve for x;
40x - 15y = 90;
40x - 15(2) = 90
40x - 30 = 90
40x = 90 + 30
40x = 120
x = 3
2. What types of organisms have cells with very large vacuoles?
Animals
Plants
Ο Ο Ο Ο.
Bacteria
Fungi
CLEAR ALL
Is a backpack a good resource
for a rescue team?
If the density of a substance is 2.18 g/mL, how would you find the density given that the mass is 0.987 kg and the volume is 4.52 x 102 mL?
Answer:
Explanation:
Convert mass in gms .. 987 gms
Density = mass/ volume
= 987/4.52 x102
= 2.18 g/mL
32 N of Force. 37 N force. How strong is the net force and in which direction?
What causes the air above a pot of boiling water to become warm?
The air transfers thermal energy to the water vapor.
The water vapor transfers thermal energy to the air.
The particles in the air lose kinetic energy.
The particles in the water vapor gain kinetic energy.
Answer: The water vapor transfers thermal energy to the air.
Explanation:
how to determine the atomic mass?
Answer: To calculate the atomic mass add up the mass of protons and neutrons.
I hope I helped!
Do you guys have viruses wit this website
Neturally an atom is neutral in charge why
Answer
Explanation:
an atom is usually define as a perfect balance of electrons and protons
Does the use of lithium cause human health problems?
Answer:
Yes
Explanation:
Lithium can cause nausea, diarrhea, dizziness, change in heart rhythm, muscle weakness, fatigue, and a dazed feeling
Continued use of Lithium could mean fine tremor, frequent urination, and thirst
Source: Webmd.com
Need help ASAP please
Answer:Melting can create steam, kind of like a nukeular plant exept no nukulear rods
What is tetanus? What are the symptoms and consequences of the disease? Who is at risk of developing tetanus? How do vaccines work? What is the history of the tetanus vaccine? Who should receive the tetanus vaccine? When should people receive the tetanus vaccine? Why is this schedule important? Has there been a change in tetanus incidence in the United States since the vaccine became available? What are the risks of vaccination versus non-vaccination? Do the risks outweigh the benefits? Are there areas in the world in which tetanus is prevalent? If so, does this affect the recommendations for US vaccination?
Answer:
The tetanus vaccine is a dose of the bacterium Clostridium Tetani, in inactive form or even a surface molecule that helps the body to actively form the antibody.
The tetanus vaccine has coverage for life, it is mandatory in those countries where the disease became common, such as the USA, Argentina, Chile, Uruguay among others.
Before a surgical act or a suspicion of exposure with this bacterium, the booster of the tetanus vaccine should be administered quickly.
Explanation:
Tetanus disease generates a tetanization of all the muscles of the organism, generating spasmodic contractions, which make it impossible to function and develop life when it affects the diaphragm as it makes breathing impossible.
Tetanization does not affect differently in age or sex, it only consists of contamination with the bacteria to be sufficient.
The sources of contagion are areas of mud or earth, rusty cutting or sharp elements, and poorly hygienic or abandoned areas. In order for the bacteria to be transmitted or the transmission route to be fulfilled, there must be a lesion of loss of continuity of the epithelium or mucosa.
Earth's revolution takes 365.25 days. What is a revolution?
Answer:
"Revolution" refers the object's orbital motion around another object.
plz mark brainliest :DD
Consider a 5.430 g mixture of FeO and Fe3O4. You react this mixture with excess of oxygen to form 5.779 g Fe2O3. Calculate the percent mass of FeO in the original mixture.
Answer:
Explanation:
A 5.430 g mixture of FeO and Fe3O4 is reacted with excess of oxygen to form 5.779 g Fe2O3. Find the masses of FeO and Fe3O4 present in the mixture.
I found the answer by doing the following:
Fe2O3 = 159.69 g/mol
FeO = 71.745 g/mol
Fe3O4 = 231.535 g/mol
5.779 g Fe2O3 / 159.69 g/mol = 0.03619 mol Fe2O3
x + y :rarrow: 0.03619 mol Fe2O3, where x = FeO and y = Fe3O4.
This implies that y = 0.03619 - x.
5.430 g = x*71.745 g/mol + (0.03619 - x)*231.535g/mol
x = 0.01846 mol * 71.745 g/mol = 1.324 g FeO
y = 0.03619 - 0.01846 = 0.01773 mol * 231.535 g/mol = 4.105 g Fe3O4
My question is why doesn't the following work:
4FeO + O2 :rarrow: 2Fe2O3
4Fe3O4 + O2 :rarrow: 6Fe2O3
_______________________
2FeO + 2Fe3O4 + O2 :rarrow: 4Fe2O3
5.779 g Fe2O3 / 159.69 g/mol = 0.03619 mol Fe2O3
Product:reactants in question are in a 2:1 ratio as given by the stoichiometric coefficients.
0.03619 mol / 2 = 0.01810 mol of FeO and 0.01810 mol Fe3O4.
0.01810 mol FeO * 71.745 g/mol = 1.299 g FeO
0.01810 mol Fe3O4 * 231.535 g/mol = 4.191 g Fe3O4
Obviously this doesn't work because the original mixture is 5.430 g and not 1.299 g + 4.191 g = 5.490 g. Why doesn't this work the way I think it should? Thank you.
During the Metric Olympics yesterday, Molly's long jump was 118.3 cm. Christy accidentally recorded her results in inches. She jumped 51.18 inches. Can you help... Who won the long jump? Christy won by about 30 cm Christy won by about 30 cm Molly won by about 25 cm Molly won by about 25 cm Christy won by about 12 cm Christy won by about 12 cm Molly won by about 10 cm
Answer: Christy won Molly by 12cm
Explanation:
Ist step
Molly's ;ong jump was 118.3cm
Christy long jump was 51.18inches
2nd Step
we change christy score to cm so we can compare
1 inch = 2.54cm.
therefore 51.18 inches = 51.18 x 2.54= 129.9972cm
Christy won molly by 129.9971cm-118.3cm=11.69 rounded to 12cm
Christy won Molly by 12cm
Please i need to pass this!
Please try
It is incorrect because it should have a total of eight electrons with two electrons between each H and O
Further explanationLewis structure shows the form of bonds that occur in the valence electrons of an element or compound
This bonding usually occurs in covalent bonds
Valence electrons are electrons used in a chemical bond
The main group elements usually have valence electron configurations in the ns and np subshells, While the transition elements in the subshells (n-1) d and ns.
Element O has 6 valence electrons
Element H has 1 valence electron
To achieve stability, the element O needs 2 more electrons which are obtained from 2 electrons from the H element, while the H element needs 1 electron to be stable
So that a covalent bond is formed
Whas the the ionic radius of strontium
Answer: 255 pm
Explanation: Hope this helps!
use the Kinetic Theory to explain the following. when you come home from school and open the door you can smell your tea being cooked
Answer:
Tea is getting hot on the stove.
2) As the tea and water gets hot, some combined molecules of tea and water will escape from the teapot.
3) Those escaped molecules now have the entire free space of the entire room to float around in, which they do (because they have high kinetic energy due to being heated).
4) Hence, in this scenario, your nose will detect a few of those molecules and you smell hot or warm tea.
5) Cold tea would be a different story. Cold beverages like cold tea do not have the kinetic energy where molecules can 'break free' of the surrounding container. Someone could be sitting in the room having a can or bottle of cold tea and you would not notice that when you walked in the door.
Which describes the elements in a given group of the periodic table?
They decrease in atomic mass as you go down the column.
They increase sequentially in atomic number from top to bottom.
They are in the same family, with similar characteristics.
Their properties change according to a pattern as you go down the column.
Answer:
They are in the same family, with similar characteristics.
Explanation:
The elements in a given group of the periodic table are in the same family and with similar characteristics.
Vertical columns on the periodic table are referred to as a group or family. Elements having the same number of electrons in the outermost shell of their atoms are placed one another in vertical columns. Each resulting vertical column is a group or family. Elements in the same group exhibit similar chemical properties because of the same number of electrons in their atoms' valence shells.You are using a calorimeter to calculate the specific heat capacity of a metallic ore. The calorimeter contains 0.50 kilograms of water at room temperature (22 °C). We heat the ore in boiling water and then drop the metal into the calorimeter and wait for the water and metal to reach the same temperature. The mass of the ore is 3.5 kilograms. We find that the water has increased in temperature to 24.3 °C. Recall that the specific heat of water is 4.18 J/g–°C. Calculate the specific heat capacity of the ore.
In the calorimeter, the heat received is the same as the heat released
Q abs = Q release
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
Q released by a metallic ore and absorbed by water at calorimeter
Q ore = Q water
Q waterm = 0.5 kg = 500 g
c = 4.18 J/g–°C.
Δt = 24.3 - 22 = 2.3
[tex]\tt Q=m.c.\Delta t\\\\Q=500\times 4.18\times 2.3=4807~J[/tex]
the specific heat capacity of the ore.Q ore = Q water = 4807 J
m ore = 3.5 kg = 3500 g
Δt = 100 - 24.3 = 75.7
[tex]\tt 4807=3500\times c\times 75.7\\\\c=0.018~J/g^oC[/tex]
What is the decomposition of 2LiCIO3
Explain three ways the periodic table is organized. Include in your essay the
definition of two listed trends and the patterns observed for each of your selected
trends on the periodic table
Answer:
The periodic table is organized in non-metals metals and metalloids, in in terms of trends and patterns you may want to talk about the the density of the elements or the mass of per unit of measurement of whatever you're going to use sorry that could be much help but I hope it helps.
Please can I have help on question e as I’m really stuck.I promise I’ll give out brainiest
The relative atomic mass of element A : 6.075 u
Further explanationThe elements in nature have several types of isotopes
Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
Mass atom X = mass isotope 1 . % + mass isotope 2.% ...
Element A
mass number of isotope 1 = 6 , percent : 92.5%
mass number of isotope 2 = 7, percent : 7.5
Relative atomic mass of element A
[tex]\tt = 92.5\%\times 6+7.5\%\times 7\\\\=5.55+0.525=6.075~u[/tex]
Which of the following is NOT
matter
Air , steam, heat , cow
Answer:
air
Explanation:
Answer:
Heat
Explanation:
Heat is a transfer of energy, but it is not made of matter. If you were talking about fire, fire is matter. But the heat from it isn't.
Pioneer species like Lichens and Mosses inhabit an area after a major disturbance, such as a volcanic eruption. Over time, other species are found in the disturbed areas, and the number of pioneer species decreases. Why does the number of pioneer species get less?
Answer:
The number of pioneer species get less as the area has more soil to support complex plants and the competition decreases the role of pioneer species.
Explanation:
Pioneer species like Lichens and Mosses inhabit an area after a major disturbance, such as a volcanic eruption. However, with time the number of pioneer species decreases.
The number of pioneer species get less as the area has more soil to support complex plants and the competition decreases the role of pioneer species.
2. Calculate the density of a rock that has a mass of 21.58 grams and causes the water in a
graduated cylinder to rise from 20.0yl to 25.4 ml.
Answer:
4.00 g/mL
Explanation:
Density is mass divided by volume (g/mL).
Mass of rock = 21.58
Volume of rock = 25.4 - 20.0 = 5.4mL
Density of rock = 21.58g / 5.4mL = 3.99629 g/mL
Round to the lowest number of significant figures which is three = 4.00 g/mL
What is the mass of 0.250 mol of chlorotrifluoromethane, CCIF3?
A. 26.1 g
B. 104 g
C. 4.78 x 10-3 g
D. 52.2g
Answer:
26.1g
Explanation:
Cclf3
=35.5
F=54/101.5
Mass=mol*mm
=0.25*1015
=26.1g
challenges we will face terraforming Mars
HELP ME PLEASE WILL MARK BRAINLIEST! DUE AT 8PM TODAY1. What is the unit of measure for the graduated cylinder? What is the maximum it can measure? What is the minimum measurement?
2. Look at the smallest division on the graduated cylinder. What amount does the smallest division measure?
3.
What are the units of measure on the plastic cup? What is the maximum amount it can measure? What is the minimum measurement?
Answer:
1. Is fortnite travis scott burger
2. Beetlejuice the second
3. The measurement is 69420
Explanation:
my mom told me
if atoms are made up of mostly space, why do objects feel like they are mostly solid
Answer:
dont question the world kid
Explanation: