Question

help on solving x^2n-2x^n-3

Most of the time people say you can't solve it but my math book says the answer is (x^n-3)(x^n+1). I understand how to factor it but... what happened to the x^2n? The 2? Because once you put it in this form after you x-factor:

(x^2n-3x^n+1x^n-3)
and you group them
(x^2n-3x^n)+(1x^n-3)

When you take the common factor out to simplify you get:
X^n(x^2-3)+1(x^n-3)

....am i doing something wrong?

Answer 1

x^(2n) = (x^n)^2

Answer 2

id solve for u^2 -2u -3, given that u=x^n

Answer 3

x^2n-2x^n-3 is ambiguous, and should be written with parentheses as amistre64 has show you here. It never hurts to use parentheses, whereas leaving out necessary parentheses can lead to great confusion.

Answer 4

u^2 -2u -3 is a quadratic expression. Which methods of factoring quadratics do you know? Apply one here.

Answer 5

i know the -b+-Radical(b)^2-4ac / 2a

Answer 6

x^n (x^2-3)

x^n x^2 is not equal to x^(2n)

x^n x^2 =x^(2+n)

Answer 7

x^n x^n = x^(n+n) = x^(2n)

Answer 8

oh i see

Answer 9

so how do i take it out of that final step after you group them?

Answer 10

i just take one x^n out?

Answer 11

factor it correctly :)

Answer 12

oh oh!!!!! so if i take only one x^2n out i get X^n left still!

Answer 13

SHHHHHH THANK YOU

Answer 14

yep

Answer 15

(x^n x^n-3x^n)+(x^n-3)

x^n (x^n-3)+(x^n-3)

etc...