Question

if x y equal to 18 and x squared plus y squared equal to 85 then find the value of x + Y

Answer 1

(X+y)²=x²+y²+2(xy)

(X+Y) ²=85+2*18

(X+Y)²=85+36

(X+Y) ²=121

X+Y=√121 =11

Answer 2

(x+y)^2= x^2+y^2 + 2xy
(x+y)^2=85+2(18)
(x+y)^2=85+36
x+y=11