MA, Stanford University
Teaching in the San Francisco Bay Area
Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts
Here I’m being given a monomial that’s being multiplied by a trinomial. You could solve it using an area or rectangle. I’m going to solve it using distributing and the only thing I want to be careful of is making sure I keep track of the negative signs, not only this negative sign that’s on my -2x, but also the negative sign that show up inside the trinomial. So let’s go ahead and do it.
This -2x gets multiplied by all 3 of those terms inside the parentheses, so -2x times x to the fourth is -2x to the fifth. -2x times -2x to the third become +4, -2 times -2 is +4 and then I have x to the fourth, and then -2x times +6 becomes -12x. That’s it, that’s my answer. It’s in standard form because the exponents go in decreasing order and I’m all set.
The only way I bet you’re making errors in these, if you’re making errors, is because you’re losing those negative signs. Just be really careful that any times you have a negative times a negative, you’re writing that product as a positive number.
