Solve using substitution.

2x-3y

x+y=9

just so you know, I know the answer its (3,6). I just need the explanation on how to get that answer using substitution.

(3,6)

Step-by-step explanation:

2x-3y = - 12

x+y=9. Solve for either y or x

-x. - x

y = - x + 9. Substitute this for the y

2x-3 (-x+9) = - 12

2x + 3x-27 = - 12. Add like terms

5x - 27 = - 12

+27. + 27. Inverse operations

5x = 15

:5. : 5

x = 3

x + y = 9

3 + y = 9. Substitute 3 for x

-3. - 3. Inverse operations

y = 6