Question

solve for x.... x^4-x^2-12=0

Answer 1

Factor

Answer 2

idk how to factor that??

Answer 3

(x^2 )(x^2 )

What two number add up to -1 and multiply to -12 ( Hint: One is positive, other is negative)

Answer 4

im pretty sure that you can only do that with x^2 as the biggest term...

Answer 5

x^2 = y

y^2 - y - 12 = 0
( y + 3 ) ( y - 4 ) = 0
y = - 3
y = 4

x^2 = y
x^2 = 4
x = 2
x^2 = - 3
x = sqrt -3
x = sqrt 3 i
i = sqrt -1

Answer 6

isn't there a different way to do it? i feel like that isn't the traditional way??

Answer 7

i will be willing to bet that this class does not use complex numbers

Answer 8

It does not need to be only x^2 to factor

Answer 9

You can factor any exponent like this

Answer 10

how...can you just show it?

Answer 11

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

Answer 12

not really sure how you got there??

Answer 13

x^2=4
x=+ or - 2

Answer 14

and that they want you to say "let
\[y=x^2\] and solve
\[y^2-y-12=0\]
\[(y-4)(y+3)=0\]
\[y=4\] or
\[y=-3\]
\[x^2=4\] or
\[x^2=-3\] second one has no real number solutions. first one has solutions
\[x=2\] or
\[x=-2\]