Why do you think many students make sign errors on this type of problem? What would be your advice to a student who has trouble with the signs? -3x(2xy + 3y - 2x)]

Question

sleepyjess · Answer

So you aren't solving the equation, you are answering the questions?

sleepyjess · Answer

If that's the case, there is no "right or wrong", it's your opinion.

anonymous · Answer

well..maybe they are trying to work the problem too fast and make a mistake with the signs. They are possibly forgetting that if the signs are alike, and they are multiplied, then the resulting sign is positive, and if the signs are different when multiplied, then the resulting sign will be negative.

anonymous · Answer

and try not to get it mixed up with adding/subtracting sign rules because they are different

anonymous · Answer

It's likely the distribution that gets 'em. Multiplying each term in parentheses by a number feels normal, but by just a minus sign... it's strange. We usually ignore the sign because we usually multiply by positives, where it's ignorable, so when there's a negative number to distribute, some tend to forget the sign.