It is good that you have tried to do it yourself!
3 x + 3 = x + 1 + x + 2 + 5
I'll try to make it easier for myself by doing like this:
YOU ARE WORKING ON THE RIGHT HAND SIDE.
1+2+5=8 YES
x+x=2x YES
8+2x=8x+2 NO Think of a page - write the number 8 and somewhere else on the page put 2 crosses.
is that he same as writing the number 2 and drawing 8 crosses. NO of course it is not.
3x +3=8+2x YES
The idea is to get all the lots of x on one side and get all the numbers without xes on the other side.
Subtract 2x from BOTH sides
3x-2x+3 = 8+2x-2x ERROR FIXED - THANKS ANONYMOUS!
x+3 = 8
now subtract 3 from both sides
x+3-3 = 8-3
x = 5
And if you have any questions, just ask.