Question

X¹10x² +9=0

Step 1. Identify the quadratic form
Let t=
We now have:
t²-10t+9=0
Step 2. Factor
Factor this and solve for t to get t
and
Step 3. Solve for
We have solved for t now we need to use this value for t
to help us solve for x. Revisit step 1 to remind you of
the relationship between t and x. Type your answers
from smallest to largest.
and +/-
x = +/-

Answer 1

x = -3, -1, 1, 3.

Explanation:

x^4 - 10x^2 + 9 = 0

Step 1

Let t = x^2

So , we have the quadratic

t^2 - 10t + 9 = 0

Step 2

Factorise:

(t - 1)(t - 9) = 0

Step 3

So, t - 1 = 0 or t - 9 = 0

t = 1, 9.

But t = x^2

So, we have x^2 = 1 or x^2 = 9

So, x = ±1, ±3.

x = -3, -1, 1, 3.