Question

what is the y-coordinate of the point of intersection for the two lines below?
-6x+7y=20
2x-3=4
help pleaseee?!

Answer 1

I think your second equation is missing a y.

Answer 2

yes it is sorry its 3y

Answer 3

Ok, so if you want to find the y coordinate you have to eliminate the x's. What can you multiply one of your equations by to make the coefficient of the x variable have the same magnitude but opposite sign?

Answer 4

3?

Answer 5

Yes!

Answer 6

Multiply the second equation by 3.

Answer 7

Then add the equations.

Answer 8

so then itll x-2=8 would i add two to each side then devide by x?

Answer 9

Huh? You shouldn't have any x's

Answer 10

Show me the steps you took.

Answer 11

-6x+7y=20
3(2x-3y=4)
________________
-6x+7y=20
6x-9y=12

x-2=8
2 2
x=10?

Answer 12

6x - 6x = x?

Answer 13

I'm pretty sure -6x + 6x = 0.
And I'm pretty sure 7y - 9y = -2y

Answer 14

So try it again?

Answer 15

y=-4?

Answer 16

Very close. You have the sign right

Answer 17

Show your steps again?

Answer 18

my practice test packet says the answer is -16 i can't see where its coming from :/ im confused

Answer 19

You are really close!

Answer 20

-6x+7y=20
+ 3(2x-3y=4)
________________
-6x+7y=20
+ 6x -9y=12
==========


This was all correct

Answer 21

Just add them up better.

Answer 22

i just realized what i did i subtracted 12 from 20 instead of adding

Answer 23

There ya go.

Answer 24

thank you so much! so do i do that everytime im trying to find the y-coordinate?

Answer 25

To find the y you eliminate the x.

Answer 26

You could also use substitution.

Answer 27

But it amounts to the same thing.

Answer 28

thanks!