Question

if x^2+y^2+z^2=14 and x+y+z=16 , find the value of xy+yz+zx

Answer 1

Hi friend!!

Given,

x²+y²+z²=14

x+y+z=16

Squaring on both sides, we get

x²+y²+z²+2(xy+yz+zx)=256

14+2(xy+yz+zx)=256

2(xy+yz+zx)=242

xy+yz+zx=121

I hope this will help you;)

Answer 2

Hey!!!!.....Here is ur answer

(x+y+z)^2=x^2+y^2+z^2+2 (xy+yz+zx)

16^2=14+2 (xy+yz+zx)

256-14=2 (xy+yz+zx)

242/2=xy+yz+zx

xy+yz+zx=121

Hope it will help you