SOLUTION: by using subsitution of linear systems how do you figure out this problem? x+y=4 -5+2y=-6 PLEASE HELP CUZ IM NOT UND

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Question 72830: by using subsitution of linear systems how do you figure out this problem?
x+y=4
-5+2y=-6

PLEASE HELP CUZ IM NOT UNDERSTANING THIS
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Solve one of the equations for a single variable (I'm going to solve for y on the top). You then plug this y value into any y you see into the 2nd equation
y=4-xSolve for y
-5%2B2%284-x%29=-6Now you can solve for x
-5%2B8-2x=-6
-2x=-9
x=9%2F2
Now plug this into x+y=4
9%2F2%2By=4Solve for y
y=4-9%2F2
y=%288-9%29%2F2
y=-1%2F2
So the solution is (9/2,-1/2) or (4.5,-0.5). In a nutshell you are substituting to eliminate one variable. This allows you to work with one variable, since you cannot simultaneously solve for 2 variables. You then take the answer of one and plug it in the other equation. Hope this helps.