Question

If x2+y2+z2+=35,xy+yz+zx23,then find the value of x+y+z

Answer 1

Answer:

(x+y+z)^2=35+46=81

x+y+z=9

Answer 2

According to identity

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

x^2+y^2+z^2 = 35 (given)

2xy+2yz+2zx=23(given)

therefore,

(x+y+z)^2= 35+23

= 58

(x+y+z) =√(58