Answer:
A pair of vertically opposite angles are always equal to each other.
First you must add the same numbers together, for instance, you wouldn't add 4y with 4 you have to add it with another number that is just like it, for instance 4y and 9y they are the same, so you can add them. So let's get to the problem now:
5y(2y-3)=(2y-3)
5y*2y=10y
(10y-3)=(2y-3)
You can do nothing to the other side because there are no numbers, that are the same.
hola quien habla español bueno ya no Adios :)