Question

a+b+c=12 and ab+bc+ca=8find a2+b2+c2

Answer 1

Answer:

128

Step-by-step explanation:

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

144=a2+b2+c2+16

144-16=a2+b2+c2

128=a2+b2+c2

Answer 2

Answer:

128

Step-by-step explanation:

a+b+c=12

squaring on both sides

(a+b+c)^2=12^2

a^2+b^2+c^2+2(ab+bc+ca)=144

a^2+b^2+c^2=144-16=128