Use the elimination method to solve the system of linear equations.

-4x-5y=-21

−4x+5y= 69   add the equations

-8x  = 48     divide both sides by -8   

x = -6

And using either equation and substituting for x, we have

-4(-6) - 5y  = -21

24 - 5y  = -21   subtract 24 from both sides

-5y =  -45    divide both sides by  -5

y = 9