Question

(i) If a + b + c = 9 and ab + bc + ca = 40, find a^2+ b^2 + c^2

Answer 1

Step-by-step explanation:

a+b+c=9

ab+bc+ca=40

We know that

(a+b+c)²=a²+b²+c²+2(ab+bc+ca)

9²=a²+b²+c²+2×40

81=a²+b²+c²+80

a²+b²+c²=81-80

a²+b²+c²=1

Hope it helps u....

Answer 2

Answer:

(a+b+c)² = a² +b²+c²+ 2(ab+bc+ca)

9² = a²+b²+c²+2(40)

81= a²+b²+c²+80

81-80=a²+b²+c²

1 = a²+b² +c²