Question

if a^2+b^2+c^2=90,a+b+c=20 then find the vale of ab+bc+ca.​

Answer 1

wait until the questions is solved

Answer 2

Answer:

Given :-

• a² + b² + c² = 90
• a + b + c = 20

Find Out :-

• ab + bc + ca

Solution :-

we know,

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

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

➭ (20)² = 90 + 2(ab + bc + ca)

➭ 400 = 90 + 2(ab + bc + ca)

➭ 400 - 90 = 2(ab + bc + ca)

➭ 310 = 2(ab + bc + ca)

➭ ab + bc + ca = 310/2

➭ ab + bc + ca = 155

∴ The value of ab + bc + ca is 155