SOLUTION: Solve the system by substitution. 3x – y = –7 x + y = –9

Algebra.Com
Question 61369: Solve the system by substitution. 3x – y = –7
x + y = –9

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
Solve the system by substitution. 1st: 3x – y = –7
2nd: x + y = –9
-----------
1st: y=3x+7
Substitute in 2nd to get:
x+3x+7=-9
4x=-16
x=-4
Substutute into 2nd to solve for y:
-4+y=-9
y=-5
Check in 1st as follows:
3(-4)-(-5)=-7
-12+5=-7
-7=-7
Cheers,
Stan H.

RELATED QUESTIONS

Solve the system by substitution. 3x - y = -7 x + y =... (answered by funmath)
Solve the system by substitution. 3x – y = –7 x + y = –9 (answered by checkley75)
Solve the system by substitution. 3x-y=-7... (answered by chitra)
Solve the system by substitution. 3x - y = -7 x + y =... (answered by praseenakos@yahoo.com)
Solve the system by substitution. 3x – y = –7 x + y = –9 (answered by mathdoc316)
How do I solve the system by substitution? 3x – y = –7 x + y = –9 (answered by checkley75)
Solve the system by substitution. 3x – y = –7 x + y = –9 (answered by nateobot)
Solve the system by substitution. 3x – y = –7 x + y = –9 (answered by malakumar_kos@yahoo.com)
Solve the system by substitution. 3x – y = –7 x + y = –9 (answered by malakumar_kos@yahoo.com)