Question

Simplify 3x2(7x2+ 2x - 4)

21x2+ 6x - 12
21x2+ 6x3- 12x
21x4+ 6x3- 12x2
21 + 6x - 12x2

to me it looks to be the first one. ?

Answer 1

i just dont know how you would get the 6x

Answer 2

look more closely at the 3rd one

Answer 3

Distributively multiply 3x^2 to all the terms inside the parentheses:

(3x^2 * 7x^2) + (3x^2 * 2x) + (3x^2 * -4)

(21x^4) + (6x^3) + (-12x^2)

21x^2 + 6x^3 - 12x^2

Answer 4

The distributive property http://en.wikipedia.org/wiki/Distributive_property is HUGE in learning algebra

Answer 5

Dang, I keep having typos:

21x^4 + 6x^3 - 12x^2

is the final answer

Answer 6

i was just about to ask about that lol

Answer 7

Ahhh, okay i was confused. thank you.

Answer 8

Both of you!

Answer 9

Also it's worth stating that multiplying exponents gives the sum of the powers. x^a * x^b = x^(a+b). To illustrate it: x^2 * x^3 = (x * x) * (x * x * x) = x * x * x * x * x = x^5