Question

if x^2+y^2+z^2=35, xy+yz+zx=23,then find the value of x+y+z

Answer 1

Answer :

x + y + z = 9

Step by step explanation :

given :-

x^2 + y^2 + z^2 = 35

xy + yz + zx = 23

to find :-

x + y + z = ?

formula used :-

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

solution :-

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

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

(x + y + z)^2 = 81

=> x + y + z = sq.root(81)

=> x + y + z = 9