Question

if a+ b +c =6 and ab +bc +ca =11 then find the value of a^3+b^3+c^3​

Answer 1

Answer:

Step-by-step explanation:

let a=3

b=2

c=1

we should check it by

ab+bc+ca=3*2+2*1+1*3

=6+2+3=11

then  

a^3+b^3+c^3

3^3+2^3+1^3

27+8+1

36

and if youn want the answer of a^3+b^3+c^3-3abc

then

(a+b+c)^2=6^2

a^2+b^2+c^2+2(ab+bc+ca)=36

a^2+b^2+c^2+2(11)=36

a^2+b^2+c^2=36-22=14

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

                  6(14-11)

                  6*3=18

so(a^3+b^3+c^3 -3abc)=18