SOLUTION: x + y = -6 11x - y = 42 Many solutions or no solutions?

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Question 13577: x + y = -6
11x - y = 42
Many solutions or no solutions?
Answer by ntnk(54) About Me  (Show Source):
You can put this solution on YOUR website!
To solve a system of equations, you can either graph, substitute, or use elimination. The easiest method for this problem will be elimination:
Add the two equations together to eliminate y:
x + y = -6
11x - y = 42
------------
12x + 0 = 36
12x+=+36
Now solve like a one step equation. Divide both sides by 12.
12x%2F12+=+36%2F12
Reduce.
x+=+3
Now plug in this value of x to one of the equations:
%283%29+%2B+y+=+-6
Subtract 3 from each side.
3+-+3+%2B+y+=+-6+-+3
Reduce.
y+=+-9
x = 3
y = -9
Remember to check:
11%283%29+-+%28-9%29 ... 42
33+%2B+9 ... 42
42+=+42


Solved by: NtNk