Without actually calculating the cubes, find the value of (−12)3+(7)3+(5)3
0
-36
-1620
-1260
x3+y3+z3−3xyz=(x+y+z)(x2+y2+z2–xy–yz–zx) When (x+y+z)=0 x3+y3+z3=3xyz −12+7+5=0 ∴(−12)3+(7)3+(5)3=3(−12)(7)(5)=−1260