Question

the value of a+b+c if a^2+b^2+c^2=41 and ab+bc+ca=20​

Answer 1

answer:-

(a+b+c)2=a2+b2+c2+2(ab+bc+ca)

(a+b+c)2=41+40

a+b+c=√81=9

Answer 2

a^2+ b^2 +c^2=41--(1)

ab+bc+ca=20---(2)

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

By substituting the values from(1)&(2)

41+2(20)=(a+b+c)^2

81=(a+b+c)^2

a+b+c=sqrt of 81

a+b+c=9