You can put this solution on YOUR website! This looks as though its from an Algebra I class (maybe pre-Algebra?). As such I will explain it in more detail than I would otherwise:
For a+a = ? how many a's are there? There are two, right? You can write a+a as '2*a' (two times a) which is shortened to just . So all you need to do is count how many a's there are and write the number in front of a single a.
a+2a = ? This is just one a plus two a's which gives you three a's, so .
What do you think happens when you have a's and b's ? Just do the above process on the a's and the b's separately and put the + sign between the two results. This process is calls "combining like terms" extends to other expressions as well.
I will do one more and leave the last one for you:
a + 3a + b + 4a + b =
(a + 3a + 4a) + (b + b) = (this step can be done in your head as you do a few of these)
Send a message if you need help.
