The main purpose of today’s lesson was to review adding and subtracting polynomials, but in a more difficult context.
- If “A is subtracted from B”, then the proper subtracting problem is B – A. For example, if (x – 7) is subtracted from (x + 10), then the resulting difference would be (x + 10) – (x – 7) = 17.
- If a negative sign is in front of a parenthesis, the effect is to take the opposite of every term inside. For example, if a problem says “Simplify: -(-2x + 9)”. The answer would be 2x – 9.