Question

Use substitution to solve 1-2.

3x – 3y = 9
x= 7 – 3y

Answer 1

Solutions are x =4 and y = 1

Explanation:

`3x-3y =9`

In this equation substitute
`x=7-3y`, we get

`3(7-3y) -3y=9\\21-9y-3y=9\\-12y= 9-21\\-12y= -12\\y=1`

now substitute y =1 in x equation,

`x=7-3(1)\\x=7-3\\x=4`

Solutions are x =4 and y = 1