Question

if (5x-y)/(5x+y) =3/7 then (4x2+y2-4xy)/(9x2+16y2+24xy) =?

Answer 1

(5x + y) / (5x-y) = 7/3

(5x+y)+(5x-y) / (5x+y)-(5x-y) = 7+3/7-3

which gives x/y = 1/2

 (4x2 + y2 – 4xy)/(9x2 + 16y2 + 24xy) = (2x-y)^2 / (3x - 4y)^2

Substituting x/y = 1/2

gives 0.