Question

If a+b+c=5 and ab+bc+ca =10 then proove that a3+b3+c3―3abc=-25

Answer 1

Answer:

Yes it's right✔

Step-by-step explanation:

(a+b+c)^2= a^2+b^2 + c^2+2(ab+bc+ca)

5^2-2×10= a^2+ b^2+c^2=5

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

=5×(5-10)

=5×-5

=-25(Proved)