Question

A+b+c=15 and a^2+b^2+c^2=83 find a^3+b^3+c^3-3abc

Answer 1

Step-by-step explanation:

(a+b+c)² = 225

a²+b²+c²+2(ab+bc+ca) = 225

83 + 2(ab+bc+ca) = 225

2(ab+bc+ca) = 142

ab+bc+ca = 71

a³+b³+c³-3abc

(a+b+c){a²+b²+c²-(ab+bc+ca)}

15 {83 - 71}

15*12 = 180