Question

4x-y=2
9x-2y=7
Use the method of substitution to solve the system of linear equations

Answer 1

Well, do it! Solve the top one for 'y', since that looks easiest, and substitute away!

Answer 2

i have been at this assignment since 7 this morning

Answer 3

Take a break. Why would you do that?

So, what's stopping you from doing this one?

Answer 4

all the numbers are looking the same, The assignment is due at 2 am my time

Answer 5

Okay, solve for y: 4x-y=2

Answer 6

1y=-2+4x

Answer 7

y=-2+4x

Answer 8

9x=-2(-2+4x)=7

Answer 9

It helps to avoid errors by using various algebraic properties.

-2 + 4x is okay, but that leading negative sign is often overlooked. I would have been happier with:

y = 4x - 2

9x-2(4x-2)=7

Answer 10

9x-8x+4=7

Answer 11

Almost there!

Answer 12

1x+4=7

Answer 13

1x+4+4=7+4
1x=11

Answer 14

No good. "-4", not "+4"

Answer 15

1x+4-4=7-4
1x=3

Answer 16

No point keeping that '1' around on the front.

x = 3.

Now, go use an original equation and find the value for 'y'.

Answer 17

4(3)-y=2
12-y=2

Answer 18

y=2-12
y=6

Answer 19

?? 2 - 12 = ??

Answer 20

y=10

Answer 21

No, that's 12 - 2.

Answer 22

-10

Answer 23

x = 3
y = -10

Does that work in the second equation?