Answer
{(1,-4)}
Work Step by Step
5y-x=-21
5y-5y-x=-5y-21
-x=-5y-21
-1(-x)=-1(-5y-21)
x=5y+21
Plug this value for x into the other equation
3x+4y=-13
3(5y+21)+4y=-13
15y+63+4y=-13
15y+4y+63=-13
19y+63=-13
19y+63-63=-13-63
19y=-76
y=-$\frac{76}{19}$
y=-4
Plug this value for y into the first equation to find x.
x=5y+21
x=5(-4)+21
x=-20+21
x=1
Therefore the solution is {(1,-4)}
