What is the completely factored form of x^4+8x^2-9

Remark

You'll see it a whole lot easier if you make a substitution so that it looks like something you have already seen

Solution

let y = x^2

x^4 = x^2 * x^2

x^4 = y * y

x^4 = y^2

Now the expression becomes

y^2 + 8 y - 9  =  z

(y + 9)(y - 1) = z

Now put the x^2 back in.

(x^2 + 9) ( x^2 - 1) = z

x^2 - 1 becomes x + 1 and x - 1. At this level x^2 + 9 can't be factored.

Answer

(x^2 + 9) (x + 1)(x - 1)

what?

step-by-step explanation:

what do you need with. i love quadrants. can you tell me ?

1.3

step-by-step explanation:

3x2=6   9x+6

bring down the 6 on both sides

6+6=12

12= 9x

divide by 9

12/9 =

1.3 =x