SOLUTION: So I have to do a problem right, they gave an example but I don't understand how they got their answer. I'm in geometry so they expect me to know it already. Here is the example pr

You're in geometry, but this is algebra. 
Do you remember any algebra?

n stands for an unknown number

3n + 3 = 2n + 6

There are 2 terms on the left, 3n and 3 
3n is a "letter term" and 3 is a 
"plain number" term.

There are two terms on the right, 2n and 6
2n is a "letter term" and 3 is a "plain number"
term.

We want ONLY "letter terms" on the left
and ONLY "plain number" terms on the right.

We get rid of the number term 3 on the left
by subtracting 3 from both sides like this:

3n + 3 = 2n + 6 
   - 3      - 3
---------------
3n + 0 = 2n + 3

We can eliminate the "+ 0" and just have

    3n = 2n + 3

Now we get rid of the letter term 2n on the right
side by subtracting 2n from both sides like this:

    3n = 2n + 3
   -2n  -2n 
   ------------
    1n =  0 + 3

We can eliminate the 0 and have
 
    1n = 3

Now we can eliminate the 1 because there is
no difference between n and 1n.  So we can
just write

     n = 3 

This is algebra you're doing,
not geometry, but there is algebra in
geometry.

Edwin