S={(0,-5)}
1) Solving that Linear System of Equation by the Substitution Method
5x+4y=-20
y=-5
2) Plugging into the first equation the value for y = -5 we have:
5x +4(-5) = -20
5x -20 = -20 Add 20 to both sides
5x =-20+20
5x =0
x=0
3) Hence, the answer is (0,-5) this system is consistent.