Question

If 3x^2+3y^2=42 and xy =-15.Find the value (x-y)^2

Answer 1

44

Explanation:

Given, 3x^2 + 3y^2 = 42

=>3(x^2 + y^2) = 42 =>x^2 + y^2 = 42/3= 14

Thus,

= (x - y)^2

= x^2 + y^2 - 2xy

= (x^2 + y^2) - 2xy

= 14 - 2(-15)

= 14 + 30

= 44