SOLUTION: Please help me solve the substituation x+y=12 and x-y=-4. I can't figure out how to solve these

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Question 213996: Please help me solve the substituation x+y=12 and x-y=-4. I can't figure out how to solve these
Found 2 solutions by Alan3354, drj:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
There's more than one method. The easiest method for this pair is elimination and substitution.
x+y=12
x-y=-4
--------- Add the 2 equations
2x = 8
x = 4
------
Sub for x into either eqn
x+y = 12
4+y = 12
y = 8
-----

Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
Please help me solve the substitution x+y=12 and x-y=-4. I can't figure out how to solve these.

x%2By=12
x-y=-4

The following will solve the system of linear equations by substitution.

Solved by pluggable solver: SOLVE linear system by SUBSTITUTION
Solve:
+system%28+%0D%0A++++1%5Cx+%2B+1%5Cy+=+12%2C%0D%0A++++1%5Cx+%2B+-1%5Cy+=+4+%29%0D%0A++We'll use substitution. After moving 1*y to the right, we get:
1%2Ax+=+12+-+1%2Ay, or x+=+12%2F1+-+1%2Ay%2F1. Substitute that
into another equation:
1%2A%2812%2F1+-+1%2Ay%2F1%29+%2B+-1%5Cy+=+4 and simplify: So, we know that y=4. Since x+=+12%2F1+-+1%2Ay%2F1, x=8.

Answer: system%28+x=8%2C+y=4+%29.



I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J