Question

If 2x2 – 2y2 = 125 and x - y = 2.5, find the value of
x + y.​

Answer 1

2x^2 - 2y^2=125

2(x^2- y^2)= 125

(x^2 - y^2) = 125/2

(x+y)(x-y) =125/2. ---------(1)

Now it is given that x-y = 2.5 ; So put the value of this in eq (1)

(x+y)(2.5) = 125/2

x+y = 125/2 × 1/2.5

x+y= 25

• ANS-- 25