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Question 485322: Select any two integers between -12 & +12, which will become solutions to a system of two equations. Write two equations that have two integers as solutions. Solve your system of equations, using the addition and subtraction method, showing all 5 steps. I chose 5, and -10 as my integers, so
x=5, and y=-10. My equations were:
2x + y = 0
-x + 2y =
-5 + -20 = -25
2x + y = 0
-2x + 4y =
-10 +-40 = -50
5y = -50
y = -10
Then to solve for x,
2x + y = 0
2(5)+ -10 = 0
2x =10
x= 5
Have I done this right, and included all the necessary steps as required?
Please help and show me. Thank you
Answer by Edwin McCravy(20059)   (Show Source):
You can put this solution on YOUR website!
You did it correctly, but I think it could be a little clearer. And be sure
to state your system of equations, and state exactly what you did in each step.
Here is how I would write it:
I chose 5, and -10 as my integers, so
x=5, and y=-10. My system of equations is:
2x + y = ?
-x + 2y = ?
I find what the numbers on the right are
by substituting
2(5) + (-10) = 10 - 10 = 0
-(5) + 2(-10) = -5 + (-20) = -25
So my system of equations is
2x + y = 0
-x + 2y = -25
To solve this system, I multiply
the second equation by 2 to
eliminate x
2x + y = 0
-2x + 4y = -50
----------------
5y = -50
y = -10
To find x, I substitute -10 for y
in the first equation and get:
2x + (-10) = 0
2x - 10 = 0
2x = 10
x = 5
Edwin
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