Question

Solve the system using substitution and describe your steps

x = y - 3
2x + y = 12

Answer 1

`x=3\\y=6`

Explanation:

`x=y-3\\2x+y=12`

We have already defined that x = y - 3, replace x for this value.

`2x+y=12\\2(y-3)+y=12`

Distribute 2.

`2y-6+y=12`

Add 6.

`2y+y=12+6`

Combine like terms;

`3y=18`

Divide by 3.

`y=(18)/(3)\\ y=6`

After having found a variable value, in this case y, replace it in the other equation; x = y - 3, to find x.

`x=y-3\\x=6-3\\x=3`