SOLUTION: For each systems of equations below, choose the best method for solving and solve. y=-x-6 x+3y = -18

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Question 1150315: For each systems of equations below, choose the best method for solving and solve.
y=-x-6
x+3y = -18
Found 2 solutions by josmiceli, MathTherapy:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(1) +y+=+-x+-+6+
(2) +x+%2B+3y+=+-18+
---------------------------
(1) +-x+-+y+=+6+
(2) +x+%2B+3y+=+-18+ Add the equations
---------------------------
+2y+=+-12+
+y+=+-6+
Now plug this result back into either equation
(1) +y+=+-x+-+6+
(1) +-6+=+-x+-+6+
(1) +x+=+0+
-----------------------
check answers:
(1) +y+=+-x+-+6+
(1) +-6+=+-0+-+6+
(1) +-6+=+-6+
and
(2) +x+%2B+3y+=+-18+
(2) +0+%2B+3%2A%28-6%29+=+-18+
(2) +0+%2B+%28-18%29+=+-18+
(2) +-18+=+-18+
OK

Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!
For each systems of equations below, choose the best method for solving and solve.
y=-x-6
x+3y = -18
y = - x - 6 ------- eq (i)

x + 3y = - 18 ----- eq (ii)

The OBVIOUS EASIEST and therefore BEST method is SUBSTITUTION, so IGNORE what the other person stated.

1)  SUBSTITUTE - x - 6 for y in eq (ii). You'll then find the value of x.

2)  Substitute the value of x into eq (i) to get the value of y.

That's IT!! Does it get any EASIER?