Answer :

3(5)+y=12
15+y=12
-15        -15
y=-3

Answer is no

3x + y = 12
2x + 3y = 1

Take the top equation and multiply it by -3

-9x - 3y = -36
2x + 3y = 1

Then, add the equations (Combine like terms

-7x = -35

Take both sides divided by -7

x = 5

The ordered pair is (5, 3) and x is infact 5, so continue

Then, plug in x for one of the other equations

3x + y = 12

3 (5) + y = 12

15 + y = 12

Subtract 15 from both sides

y = -3 

Your ordered pair is (5, 3) but the y is not -3

No, the ordered pair is not a solution of the system of linear equations