Monday, February 15, 2010

CAUTION: Multiplication before addition or subtraction.

Be aware that "they" like to dangle addition or subtraction in front of us like follows:

5 - 2(x + 7) = 11

It is very much tempting to subtract 5 - 2, isn't it? DO NOT DO IT... the order of operations requires that we multiply (or distribute) before subtraction. The solution follows: