The non-negative real numbers x, y, and z satisfy the two equations

x^2 + y^2 + z^2 = 9

xy + xz + yz = 18

What is the sum of x, y, and z?

Guest Feb 1, 2022

#1**+1 **

Use the following algebraic identity:

(x + y + z)^2 = x^2 + y^2 + z^2 + 2(xy + xz + yz) = 9 + 2(18) = **45**

CubeyThePenguin Feb 1, 2022