Question

Hello! I need some help on subtracting polynomials, an explanation or step-by-step instructions would be great! ^_^

Subtract and simplify:
(3x^2 – 6x + 7) – (x^2 – 6x + 4)

A. 4x^2 – 6x + 3
B. 2x^2 + 6x + 3
C. 2x^2 + 3
D. 2x^2 + 6x + 11

Answer 1

It's C

Answer 2

Yes, I agree with torpaige.

Answer 3

I am glad that you know the answer, but I was looking to find an explanation, NOT an answer.

Answer 4

If you could tell me how you got there and what steps you took to get there, then that would be great! @torpaige @SwagteenFTW

Answer 5

Haha okay. It's actually really simple.
It's just a matter of squishing the two sets of numbers together.
3x^2 minus x^2 will give you 2x^2
-6x (flip the sign to add because of the double negative; so..) plus 6x will give you 0, cancelling that part of the equation out
And 7 minus 4 is 3

Answer 6

Is this what you are saying: \[(3x^2 - 6x + 7) - (x^2 - 6x + 4)\]\[(3x^2 + -6x + 7) + ( -x^2 + -6x - 4)\]\[(3x^2 + -6x + 7) + ( -x^2 + -6x + -4)\]\[3x^2 + (-6x) + 7 + (-x^2) + (-6x) + (-4) \]\[3x^2 + (-x^2) + (-6x) + (-6x) + 7 - 4\]\[3x^2 + (-x^2) + (-12) + 3\]\[2x^2 - 12~+~3\]

Hmm... What did I do incorrect to get -12?

Answer 7

@torpaige ^^

Answer 8

@BlossomCake Sweet heart that's not one of the answers.

Answer 9

I know. ._. That's why I asked "What did I do incorrect to get -12?"

Answer 10

@torpaige ^^

Answer 11

Hahaha Ahh. You add the second 6X because before the number and before the paras, theres a minus sign. If there are two minus signs, it makes it addition. so the first -6x plus the second 6x equals 0

Answer 12

Yep, I just looked up and figured it out... Thanks anyways! :)