Question

Help me I have no idea how to do 18

Answer 1

First, subtract px2 from both sides.

Now you have:

x3 - px2 = (1 - p) x1

Next, divide both sides by (1 - p)

So now you have

x3 - px2/(1 - p) = x1

...as your final answer

*You can decide if you want to leave the parenthesis in your final answer, I left them there so it could be visible where I put them. :)