Can you answer and explain how to do this?

1x-4-3x=2x-3-1

Here is what you have to do first, combine like terms. On the left side do x-3x (you can do 1x-3x because x is just 1 variable, so I can see why you put 1x instead of x). Then combine -3-1. Then add the x answer on the left side to the 2x on the other side then you can figure out the rest. The reason why I want you to figure out the rest is because I'm just helping you and you need to get the answer yourself. 

If i think this is what your asking, he should look at the grams or pounds/ounces and compare the to their cost then max can identify which one is proportional and which is not ( i think xd)