Question

How do you multiply `( x-4 )/(5x^2(x+y) )*( y^2-x^2)/(16y-4x)`?

Answer 1

`((x-4)(y-x))/(20x^2(4y-x))`

Explanation:

`(x-4)/(5x^2(x+y)) xx (y^2-x^2)/(16y-4x)`

Factorise each expression as far as possible:

`=((x-4))/(5x^2(x+y)) xx ((y+x)(y-x))/(4(4y-x))`

Cancel any common factors.

`=((x-4))/(5x^2cancel((x+y))) xx (cancel((y+x))(y-x))/(4(4y-x))`

`=((x-4)(y-x))/(20x^2(4y-x))`