Hey all i know this is really basic but i have hit a wall

(d / a+b) * (5a + 5b / 2d^2 + 2d)

i can get the answer but im not sure what im actually doing S:

i khow to multiply problem like (1/2) * (1/2) = 1/4 but what confuses me in this problem is the denominator a+b not sure how to multiply the other denominator with it.

My workings

(d / a+b) * (5a + 5b / 2d^2 + 2d)

i just divide by common factors first step

numerator 5a + 5b to 5 ( a+b)

then denominator 2d (d + 1)

then i just divided both numerator and denominator by common factors (a+b) and d

so i got the answer 5 / 2 (d + 1)

how would you guys solve it? sorry if my reasoning bit over the place, any chance you can show me your working so i can aware myself.

thank you.