Question

if a+b+c=9 and ab+bc+ca=26.find a²+b²+c²​

Answer 1

We know the formula:

(a+b+c)² = a² + b² + c² + 2(ab+bc+ca)

Given:

a+b+c = 9 & ab+bc+ca = 26

Now putting the values in the above formula,

We get,

(9)² = a² + b² + c² + 2×26

81 = (a² +b² +c²) + 52

(a² +b²+c²) = 81-52

(a² + b² + c²) = 29 (Answer)

hope it helps you

Answer 2

Step-by-step explanation:

a+b+c=9

Take square on both sides

(a+b+c)^2=9^2

a^2+b^2+c^2+2(a+b+c)=81

a^2+b^2+c^2=+2×26=81

a^2+b^2+c^2+52=81

a^2+b^2+c^2=81-52

a^2+b^2+c^2=29