Question

If a + b + c = 9 and ab + bc + ca = 26, then find a2 + b2 + c2.

Answer 1

Step-by-step explanation:

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

(9)^2=a^2+b^2+c^2+2(26)

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

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

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

Answer 2

Answer:

(a+b+c)² = a²+b²+c²+2(ab+bc+ca)

(9)² = a²+b²+c²+2(26)

81 = a²+b²+c²+52

81-52 = a²+b²+c²

29 = a²+b²+c²