Question

If a+b+c=56 and, a^2+b^2+c^2=20 find ab+bc+ac. Answer this fast and be marked as the brainliest.

Answer 1

★ Given :

a + b + c = 56

a² + b² + c² = 20

★ To find :

value of ab + bc + ca

★ Solution :

We know that ,

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

by putting the values

→ (56)² = 20 + 2 (ab + bc + ca)

→ 3136 = 20 + 2(ab + bc + ca)

→ 3136 - 20 = 2(ab + bc + ca)

→ 3116 = 2(ab + bc + ca)

→ ab + bc + ca = 3116/2

→ ab + bc + ca = 1558 ..

Answer 2

Hey mate ,

Given that ,

•     a+b+c=56, a^2+b^2+c^2=20
• And said to find the value of ab+bc+ca

We know that,

• (a+b+c)^2=a^2+b^2+c^2+2ab+2bc+2ca

SOLUTION :

• (a+b+c)^2=a^2+b^2+c^2+2ab+2bc+2ca

• (56)^2=20+2ab+2bc+2ca

• 3136=20+2ab+2bc+2ca

• 3136-20=2ab+2bc+2ca

• 3116/2=ab+bc+ca

• 15558=ab+bc+ca