Question

Evalute : `((2x)/7 - (7y)/4)^2`

Answer 1

`((2x)/7 - (7y)/4)^2`

We know that
( a - b )² = a² - 2ab + b² 

∴ `((2x)/7 - (7y)/4)^2 = ((2x)/7)^2 + ((7y)/4)^2 - 2 xx (2x)/7 xx (7y)/4`

                                = `(4x^2)/(49) + (49y^2)/16 - xy`