SOLUTION: Solve the following systems by substitution. Substitute the expression in the second equation into the first equation and solve. (If the system has no solution, enter NONE for each

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Solve the following systems by substitution. Substitute the expression in the second equation into the first equation and solve. (If the system has no solution, enter NONE for each      Log On


   

Question 362322: Solve the following systems by substitution. Substitute the expression in the second equation into the first equation and solve. (If the system has no solution, enter NONE for each answer.)
x-y= -4
y= 3x+6

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
Replace y in the 1st equation by 3x+6 (from the bottom equation):
x - (3x+6) = -4,
x - 3x-6 = -4,
-2x = 2,
x = -1. Then y = 3*-1 + 6 = -3+6 = 3.