Question

use a substitution to solve the system of equations. 3x-3y=30 , -2x+8y=-26

Answer 1

answers are
a. (4,-6)
b. (9,-1)
c. (17,1)
d. infinitely many solutions

Answer 2

Firstly you need to multiply both eq. so that x or y have the same values.Then you can add or substract it.
For example: both equation I multiply by 2.So the equation should be like this,
6x-6y=60
-6x+24y=-78

Answer 3

You can see that the value of x is same right? So you can add 'plus sign' to the first eq. 6x-6y=60
Then you will get 18y=-18 which y=-1

Answer 4

ok what do i do next ?

Answer 5

So last step you need to substitute the value of y into the any the first eq. before you multiply by 2.
For example: 3x-3y=30
So put the y value into the eq. You will get the x value.
Ok?

Answer 6

So x is 9 ?

Answer 7

Yes,that's it.

Answer 8

Thanks

Answer 9

Wc.