Question

Choose the correct simplification of the expression -6x^2(4x - 7x^2 - 2).

42x^4 + 24x^3 - 12x^2

-42x^4 + 24x^3 - 12x^2

-13x^4 - 2x^3 - 8x^2

42x^4 - 24x^3 + 12x^2

Answer 1

distribute -6x^2 over each term in the parentheses

that is multiply each term in the parentheses by -2x^2

Answer 2

Its D

Answer 3

remember when you are multiplying the terms in x you ADD the powers

eg x^2 * x = x^(2+1) = x^3 [note x = x^1]

Answer 4

@jagr2713 - please just don't give the answer - read Code of Conduct

Answer 5

I'm sorry, I'm so confused lol.I'm following along but there's no way I could do this by myself.

Answer 6

i'll start it off for you

-6x^2(4x - 7x^2 - 2)

= -6^2 * 4x - 6x^2* -7x^2 - 6x^2 * -2

the first multiplication is

-24 x^(2+1) = -24x^3

are you ok with that? remember that a negative * positive = negative:- 6*-4 = -24

Answer 7

* error in third line- it should be -6x^2 not -6^2

Answer 8

Wait, so did you just distribute ?

Answer 9

yes

Answer 10

yes and worked the first part out for you

Answer 11

Okay, and then next step was multiplying the terms.
Now what's the next part ??

Answer 12

-6x^2 * -7x^2 = -7*-6 x^(2+2) = 42 x^4

Answer 13

now can you work out -6x^2 * -2 ?

Answer 14

after multiplying out the 3 parts just put them together

Answer 15

I feel so stupid D; But no, can you help me ?

Answer 16

How do we put them together ?..

Answer 17

well you just multiply the numbers first
6 * -2 = ?

Answer 18

-12 ?

Answer 19

yes thats right
the last term = -12x^2

so putting them together you get
-24x^3 + 42x^4 - 12x^2

Answer 20

now you can rearrange these as long as you take the sign with you
this is the same as
42x^4 - 24x^3 - 12x^2

which is the last option

Answer 21

jagr had the right answer but didnt explain how to get it

Answer 22

Thank you so much for working through this with me.

Answer 23

yw hope you have learned something

Answer 24

OH hold on - theres an error
the last term is -6x^2 * -2 = + 12x^2

Answer 25

thats still D

Answer 26

-6 * -2 = +12

Answer 27

somewhere along the line -6 became 6 - my error