I went through basic algebra literally like 20+ years ago, I generally understand it well, but vaguely remember specifics if any.
Right now I am doing an advanced programming course and one question had an answer which did some basic algebraic simplification. I do not understand how this works anymore. Here is the steps of simplification it went through:
- Step $1:$ $a \cdot b + a \cdot c - (b + c)$
- Step $2:$ $a \cdot (b + c) - (b + c)$
- Step $3:$ $(a - 1) \cdot (b + c)$
I understand step 1 to step 2 fairly well. But how does step 2 end up as step 3?
Could someone point me to a video, tutorial or something that would refresh my understanding of whatever it is that allowed step 2 to get to step 3?