Question

If x+y+z=12 and xy+yz+zx=22, find x^2+y^2+z^2

Answer 1

Hi friend!

Given, x+y+z=12 and

xy+yz+zx=22

Squaring on both sides, we get

( x+y+z )^2= 144

x²+y²+z²+2(xy+yz+zx)=144

(bcz we know ( x+y+z)^2 = x²+y²+z²+2(xy+yz+zx))

It is also given that xy+yz+zx=22

→x²+y²+z²+2(22)=144

x²+y²+z² =144-44

x²+y²+z² = 100

I hope this will help you ;)