Answer :

All you have to do is combine 3x and 5x to = 8x. You can't combine 8x and 67y because they have different variables. so it's 8x+67y. 
3x + 5x = 67y
8x = 67y
this will be the final answer you can't divide with those two numbers because they don't have the same verbal.

i hope it helps.