Donnel practiced the piano 3 hours longer than marcus. together they practiced the piano for 11 hours. how many hours did each boy practice? ?

Here is the equation:  ⇒

You need to get "x" by itself so minus 3 from each side

 ⇒  ⇒ 

Divide 8 by 2

 ÷ 

x=4

So each 4 is equivalent to 4 

Lets check:

 ⇒  ⇒ 

So that means that Marcus practiced the piano for 4 hours and Donnel practiced for 7