A student solved a system of equations by elimination. The answer is not correct. Describe the error in the solution.

Original Problem:

3x−2y=8

x+y=2

Student Work:

3x−2y=8

2x+2y=2

5x=10

x=2

Answers

Answer 1

The student went from x+y = 2 to 2x+2y = 2, which is not correct. They multiplied the left side by 2, but forgot about the right hand side.

They should have gone from x+y = 2 to 2x+2y = 4 after multiplying both sides by 2.

So they should have this new equivalent system

[tex]\begin{cases}3x-2y = 8\\2x+2y = 4\end{cases}[/tex]

Add straight down and we end up with the new equation 5x = 12 which solves to x = 12/5 = 2.4

Use that x value to solve for y. You should get y = -2/5 = -0.4


Related Questions

Find the value of x so that f(x) = 13 f(x) = 3x+4
A. 2
B. 3
C. 6
D. 4

Answers

Step-by-step explanation:

3x + 4 = 13

3x = 13 - 4 = 9

x = 9/3 = 3

x = 3

option B is correct

hope this answer helps you dear! take care

B is the correct answer

I need help brainiest to the correct answer!

Answers

#1

y=4

x=5

y is decreasing

5-4=1

[tex]\\ \sf{:}\dashrightarrow \dfrac{x-y}{x}(100)=\dfrac{1}{5}(100)=1(20)=20\%[/tex]

#2

x=5y=8

y is increasing

8-5=3

[tex]\\ \sf{:}\dashrightarrow \dfrac{3}{8}(100)=37.5\%[/tex]

Mary wants to buy one large pizza, one medium pizza, and three drinks. The drinks cost $p$ dollars each, the medium pizza costs two times as much as one drink, and the large pizza costs three times as much as one drink. If Mary started with $30$ dollars, how much money would she have left after making all of her purchases? Give your answer as an expression of $p

Answers

$ (30-8p)

Step-by-step explanation:

3 DRINKS- 3P

MEDIUM- 2p

large- 3p

so plus 8 p

Can you write 8x=1 as a quadratic equation?

Answers

Answer:

  yes

Step-by-step explanation:

The root of the given linear equation can be made to be a repeated root of a quadratic equation:

  (8x -1)² = 0

Write an explicit rule and recursive rule for a geometric sequence with a 2nd term of 6 and a 3rd term of 12.

Answers

Answer:

57777788999999888889999

Louisa is 5 feet 4 inches tall.
How tall is she in inches?

Answers

Answer:

64 inches

Step-by-step explanation:

We need to convert feet to inches

5 ft = 5*12

= 60

5ft is 60 in

1 ft = 12 in

Add 60 in & 4 in

= 64 in

Hope this helps! Please rate it and press the heart button! Thanks!

Answer:

64

Step-by-step explanation:

12 inches= 1 foot

5 feet= 60 inches

60+4= 64 inches

please answer it i need help

Answers

This is karma for doing this to some one else :)

regdcd gvfd vcds xgrcd xre dse dxf crdx vcfx gvf c fcvr fvcrdgbv

PLZ ANSWER QUICK. WILL GIVE BRAINLY. NO EXPLANATION NEEDED.

Answers

Answer:

None of these are correct

Step-by-step explanation:

XZ = XY + YZ = 48 + 50 = 98


Joe is making a rectangular frame in woodshop class. The length of the frame is 2 inches
longer than the width of the frame. The perimeter of the frame is 24 inches. Write an
equation that could be used to determine w, the width in feet, of the frame.

Answers

Answer: The width is 5.

Step-by-step explanation:

'(2+w)+(2+w)+2w=24

4+4w=24

W=5

!! please help me i’ll mark brainliest !!

Answers

Answer:

1/2=(A+B)

area of triangle=1/2×base×height

Bethany has a mother, 6 sisters, 3 aunts and 2 grandmothers. How many girls are in this family?​

Answers

Answer:

13

Step-by-step explanation:

1 plus 1 plus 6 plus 3 plus 2 equals 13

x/7 + y/5 =12
2x/5 - y/7 =9

Answers

Answer:

x = 35 ,y = 35

Step-by-step explanation:

x = 35

y = 35

I WILL GIVE BRAINLIEST!! PLS HELP

Answers

Answer:

Angle PRQ is the same as NRM so therefore one of the three angles for both triangles is the same. Angle QPR and NMR are both 90 degrees and so the last angle must be the same in order for the three angles to be 180 degrees in total.

Step-by-step explanation:

Hope This Helps!!!

What kind of math is this???





???

The ratio of roses to carnations to daisies in
a flower bouquet is 2:5:6. The bouquet has
39 flowers. How many carnations are in the
bouquet?

Answers

Answer:

10

Step-by-step explanation:

10 10 10 1010 10 101 10 10 1o

A line is drawn so that it passes through the points (-3, -1) and (4, 2).

a. What is the slope of the line?

b. Using the point (4, 2) and the slope found above, write the equation of the line in point-slope form.

Answers

Answer:

y - 2 3/7 (x-4)

Step-by-step explanation:

A) To find slope, use the equation:where  and  are the x and y values of one coordinate point  , and  and  are the x and y values of another coordinate point . Since we are given two coordinate points, (-3,-1) and (4,2), that means we can find the slope using the slope equation.  

Let's choose (4, 2) as your  point and (-3, -1) as your  point, but you can switch those if you want! That makes  and x^1 = -3, y1 = -1 . Plug these values into the slope equation:

The slope of the line is 3/7.

B) Remember that the general equation for point-slope form is, where m = the slope,  = the x value of a coordinate point on the line, and  = the y value of the same coordinate point on the line.  

You are given (4, 2) as one of the coordinate points. That means  = 4 and  = 2. We found the slope, m =  in part A. Now plug these values into the general equation for point-slope form to find your point-slope form equation:

Your point-slope form equation is y - 2 3/7 (x-4).

Answer:

a. 3/7 b. y=3/7x+2/7

Step-by-step explanation:

(-1-2)/(-3-4)=3/7

slope is 3/7

apply point for answer

2=3/7(4)+n

n=2/7

apply

y=3/7x+2/7

Please help me quickly

Answers

Step-by-step explanation:

a full circle (turning around a point a full turn) is 360°.

so, all these angles together must be 360°.

90 + 33 + 165 + 20 + x = 360

308 + x = 360

x = 52°

20 pts But help me with this problem.

Answers

Answer:

You put 10 pts by accident lol.

Nahh it’s just 10pts bro



HELP NEEDED ASAP

Order the numbers from least to greatest​

Answers

Answer:

-31/6, -/26, -5, -5/6

first choice is the answer

Find the slope of the line y=-1/4x+1

Answers

Answer:

slope is -1/4 the number before the x is the slope

Step-by-step explanation:

Answer:

The slope is -1/4

Step-by-step explanation:

The equation is written in slope intercept form

y = mx+b  where m is the slope and b is the y intercept

y = -1/4x +1

The slope is -1/4 and the y intercept is 1

can someone please tell me what is 12 x 8 +5?

Answers

Easy!

Use BODMAS

first solving 12×8

which is = 12×8=96

than add +5

so, 96+5= 101

Hope This Helps

Answer: 12x8=26+5= 31

Step-by-step explanation:

Find the perimeter.Simplify your answer.

Answers

Answer:

22w - 18

Step-by-step explanation:

To find the perimeter we have to add up all the sides

10w-10+w+1+10w-10+w+1

combine light terms

22w - 18 would be our answer

Answer:

2(10w-10)+2(w+1) =

20w-20+2w+2 =

22w-18

round 2,419 to the nearest hundred​

Answers

Answer:

2,400

Step-by-step explanation:

Can I please have brainliest?? thanks!! have an awesome day and good luck with your math :)

Answer:

2,400

Step-by-step explanation:

Hello! I need help with this

Answers

Answer:

y = -16.25

Step-by-step explanation:

[tex]26=-\frac{8}{5}y[/tex]

It can also be written as

[tex]26=\frac{-8y}{5}[/tex]

-8y = 26 * 5

-8y = 130

y = 130/-8 = - 65/4 = -16.25

A line contains the points (-3,-9) and (4,5). What is the point-slope form of the line? A. y + 9 = -2 (x + 3)
B. y - 5 = 3 (x - 2)
C. y - 9 = 2 (x + 3)
D. y + 9 = 2 (x + 3)​

Answers

Answer:

D

Step-by-step explanation:

First find the slope.

[tex]Slope=\dfrac{y_{2}-y_{1}}{x_{2}-x_{1}}\\\\=\dfrac{5-[-9]}{4-[-3]}=\dfrac{5+9}{4+3}\\\\\\=\dfrac{14}{7}=2[/tex]

Point slope form:

y - y1 = m(x -x1)

y -[-9] = 2 (x - [-3])

y +9 = 2 (x + 3)

What is the value of x?

Answers

Answer:

more ... The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try! A variable doesn't have to be "x", it could be "y", "w" or any letter, name or symbol.

Answer:

[tex]x = 12[/tex]

Step-by-step explanation:

For resolve this problem I use trigonometry identities.

[tex]sin(\theta) = \frac{OP}{H}[/tex]

Where [tex]\theta[/tex] is the angle of the triangle (45), [tex]OP[/tex] is the opposite side of the angle ([tex]6\sqrt{2}[/tex]) and the [tex]H[/tex] is the hypotenuse ([tex]x[/tex]).

Replace the know values in the relation

[tex]sin(45) = \frac{6\sqrt{2}}{x}[/tex]

Isolate [tex]x[/tex] of the equation and solve

[tex]\frac{6\sqrt{2}}{sin(45)} = x\\\frac{6\sqrt{2}}{\frac{\sqrt{2}}{2}} = x\\\frac{12\sqrt{2}}{\sqrt{2} } = x\\12 = x[/tex]

So the final answer is [tex]x = 12[/tex]

Which statement describes the system of equations? The system has infinitely many solutions. The system has no solution. The system has one solution The system has one solution

Answers

It’s B the system has no solution

Please help!!!!!!!!!!!!!!!! Find the scale factor for the side lengths

Answers

Answer:

Scale factor is 1/4

Step-by-step explanation:

You can easily calculate the scale factor of anything by dividing the new length by the old one. Then just simplify if necessary.

TS is 8, and T'S' is 2, so:

[tex]\frac{2}{8}=\frac{1}{4}[/tex]

edit: fixed fraction

Picture has it Solving Quadratics & Other Equations

Answers

Answer:  p=6 and r=8

Step-by-step explanation:

A)  Add exponents when multiplying:  [tex]x^{4}[/tex] *  [tex]x^{2}[/tex] = [tex]x^{6}[/tex] p = 6

B)  Multiply exponents when raised to a power:   r = 8

Stacy shares 164 peppers equally between 5 of her friends. How many peppers does each friend get? How many are left over?

Answers

Answer:

each person gets 32 papers and  there are 4 left over

Step-by-step explanation:

Each friend gets 32 as 164/5
4 peppers are left over

pls make me brainliest and this is the right answer

Which direction does the decimal point move in when you divide by powers of 10 greater than 0?

Answers

Answer:

the left side is the answer

the decimal point will move towards right
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