Question

if a + b + C is equal to 7 and a b + BC + CA is equal to 20 find a square + b square + c square​

Answer 1

Hey there!

Answer:

a² + b² + c² = 9

Step-by-step explanation:

Given,

(a + b + c) = 7     .................(i)

(ab + bc + ca) = 20

squaring both sides of eq. (i);

(a+b+c)² = 7²

⇒ a² + b² + c² + 2(ab + bc + ca) = 49

⇒ a² + b² + c² + 2*20 = 49

⇒ a² + b² + c² = 49 - 40

⇒ a² + b² + c² = 9

Hope it Helps You!