>>501914you want the b's to eliminate each other.
so what can you multiply the 3b by, and the -2b by so that when they add, they're gone?
I know for non-mathematically inclined ppl this is hard, but you just "see" that if you can make the 3b a 6b, and the -2b a -6b, the 6b and the -6b cancel each other out.
very lengthy explanation to follow:
now in this case, all you had to do was multiply the 3 by 2, and 2 by 3, (in other words by each other) but in some cases you'll have something like
10x
-4x
then you'll find you only need to multiply the top by 2, and the bottom by 5 to get 20 and -20 and they cancel each other out. if this is too hard, just multiply by the other (multiply to by 4 and bottom by 10) and they still cancel each other out (40 and -40), but you may have to multiply and add larger numbers.
