Question

If a+b+c=9and a^2+b^2+c^2=35,find the value of (a^3+b^3+c^3-3abc)

Answer 1

a+b+c=9,
Squaring both the sides,
(a+b+c)²=(9²)
a²+b²+c²+2(ab+bc+ca)= 81
35+2(ab+bc+ca)= 81
2(ab+bc+ca)= 81-35
ab+bc+ca= 46/2=23

a³+b³+c³-3abc= (a+b+c)(a²+b²+c²-(ab+bc+ca)
a³+b³+c³-3abc=(9)(35-23)
a³+b³+c³-3abc= 9 x 12= 108


Hope it helps you....

Answer 2

this must be the right answer