Question

Find all the zeroes of the equation.
-3x^4+27x^2+1200=0

Answer 1

Factor out -3 first

Answer 2

ok so -3 (x^4+9x^2+400)

Answer 3

-3(x^4-9x^2-400)

Answer 4

Now find two factors of -400 that add up to -9

Answer 5

I'll give you a hint: One of them is -25

Answer 6

16,-25

Answer 7

Now write the factors of x^4-9x^2-400

Answer 8

im confused

Answer 9

Fill in the blanks:
x^4-9x^2-25=(x^2- )(x^2+ )

Answer 10

(x^2-16)(x^2-25)

Answer 11

So now we have this:
-3(x^2-25)(x^2+16)=0

Answer 12

ok

Answer 13

Set each factor equal to 0 and solve each equation.

Answer 14

-5,5?

Answer 15

Those are two of the answers. Now do the other equation.

Answer 16

-4,4

Answer 17

\[x^2+16=0\]
\[x^2=-16\]
\[\sqrt{x^2}=\pm \sqrt{-16}\]

Answer 18

\[x=\pm \sqrt{(-1)(16)}\]
\[x=\pm \sqrt{-1}\sqrt{16}\]
\[x=\pm i(4)= \pm 4 i\]

Answer 19

ok

Answer 20

is that the final answer

Answer 21

Those are the final 4 answers.
Since your equation has x^4, there should be 4 answers.

Answer 22

ok thank you!

Answer 23

yw