Question

Can someone give me a quick refresher on how to do this kind of problem?

Simplify (2m3 + 3m2 − 7m) − (5m3 − 9m).

Answer 1

I don't remember how to do it. If you could just explain so I understand?

Answer 2

-3M^2+3M^3+2M is your answer. You can also use mathway.com for these answers

Answer 3

Explain how you got it please?

Answer 4

Multiply -1 by each term inside the (
)

Answer 5

combine like terms.

Answer 6

Okay, got it! I remember now :) thanks!!!

Answer 7

Welcome!

Answer 8

You are subtracting two polynomials.
You rewrite the first polynomial as it is just simply dropping the parentheses.
To take care of the subtraction and the parentheses around the second polynomial, think of the minus sign before the second set of parentheses as a -1 multiplying the polynomial inside the second set of parentheses. You use the distributive property and get rid of the seciond set of parentheses by multiplying every term inside by -1. That means simply get rid of the parentheses by changing the sign of every term inside the second set of parentheses.
Then you combine like terms. Like terms are terms that have the same variable(s) and exponents. These terms can be added or subtracted.

Answer 9

Answer above "-3M^2+3M^3+2M" by @ashleyvee is incorrect

Answer 10

your answer is incorrect. i have a calculator that specializes in these problems.

Answer 11

@ashleyvee In both polynomials, there is one single term with m^2. It's 3m^2 in the first polynomial. How did it change to -3m^2 in your answer when there is nothing to combine it with?

Answer 12

go to mathway and look up the steps.

Answer 13

(2m3 + 3m2 − 7m) − (5m3 − 9m)
1. Get rid of the first set of parentheses:
2m3 + 3m2 − 7m − (5m3 − 9m)
2. Get rid of second set of parentheses, distributing the negative:
2m3 + 3m2 − 7m − 5m3 + 9m
3. Combine like terms:
2m^3 - 5m^3 + 3m^2 -7m + 9m
-3m^3 + 3m^2 + 2m

Answer 14

@ashleyvee
Thanks for the tip. I had never heard of mathway.
I just went there. The answer according to mathway is:
-3m^3 + 3m^2 + 2m
which is not what you have.

Answer 15

i got the same answer as you, just misstyped the steps!