Answer:
0
Step-by-step explanation:
x+y=5
x^3+y^3+15xy-125
(x+y)(x^2-xy+y^2)+15xy-125
5(x^2-xy+y^2)+15xy-125
5x^2+5y^2-5xy+15xy-125
5x^2+5y^2+10xy-125
5[x^2+2xy+y^2]-125
5(x+y)^2-125
5(5)^2-125
125-125
