Question

a+b+c=15,a^2+b^2+c^2=83 find the value of a^3+b^3+c^3-3abc

Answer 1

you can also screch Google

Answer 2

Answer:

180

Step-by-step explanation:

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

a+b+c=15;

=>(a+b+c)^2=15^2

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

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

=>(83-225)/2= -ab-bc-ca

=>-142/2=-ab-bc-ca

=>-ab-bc-ca= -71

Thus substituting the values in (i).. we get,

a^3+b^3+c^3-3abc = 15(83-71)

=>a^3+b^3+c^3-3abc=15*12

=>a^3+b^3+c^3-3abc=180

thus 180 is the ans.