
Candace S. answered 03/05/16
Tutor
4.9
(28)
A day without Math is like a day without sunshine!
Hi Anna,
-2x+5y=1
7x-10y=-11
If (x,y) is a solution to the system of equations above, what's the sum of x and y?
7x-10y=-11
If (x,y) is a solution to the system of equations above, what's the sum of x and y?
Solve this system by Elimination Method;
-2x+5y=1 2[-2x+5y=1] -4x-10y=2
7x-10y=-11 7x-10y=-11 7x-10y=-11
7x-10y=-11 7x-10y=-11 7x-10y=-11
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3x=-9
x=-3
Substitute x=-3 into 1st equation
-2x+5y=1
-2(-3)+5y=1
6-5y=1
-5y=-5
y=1
The solution is (x,y)=(-3,1), therefore, x+y=-3+1=-2
ANSWER: -2