S ={-2,3}
Solving the system, by the addition method:
x + 5y = 13 Multiply that equation by -5
5x + 6y = 8
-5x -25y = -65 Add both equations
5x + 6y = 8
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-19y=-57
19y = 57 Divide by 19
y=3
x + 5y = 13 Plug y=3 in the first equation
x+5(3) =13
x+15=13 Subtract 15 from both sides
x=13-15
x=-2
S ={-2,3}