Question

if a + b + c = 9 and a b + bc + ca = 26. find the value of a^3+ b^3+c^3-3abc

Answer 1

formula of a cube plus b cube plus c cube=
(a+b+c) ( a square + b square + c square minus A B minus bc minus AC )
9*

Answer 2

hey here is ur answer

a^3+b^3+c^3-3abc= (a+b+c)(a^2+b^2+c^2-ab -bc-ac)

given a+b+c=9
squaring on both sides

(a+b+c)^2=9^2
a^2+b^2+c^2+2(ab+bc+ac)=81
a^2+b^2+c^2=81-2(26)
= 81-52
=29

a^3+b^3+c^3-3abc= (a+b+c)(a^2+b^2+c^2-ab -bc-ac)
a^3+b^3+c^3-3abc= (a+b+c)[a^2+b^2+c^2-(ab +bc+ac)]
=9[29-(26)]
9*3
=27


I hope this helps u