Answer:
x = -1, x = 1
Step-by-step explanation:
Factor the equation. (It's a difference of squares, so we know the form will be (a-b)(a+b).)

Test this by FOILing it out, if you're unsure. This is something it can be good to memorize!
Set it equal to 0.

Separate the two parenthetical expressions by the Zero Product Property.

Solve for x!

The answer is

In the choices; the coefficients 21, 32 and 10 are not perfect squares.
Answer:
C. 17,820
Step-by-step explanation:
30,500-12,680= 17,820
Answer:
Step-by-step explanation:
I assume that you mean
sec(x)-tan(x) = 1 / ( sec(x) + tan(x) ) , right ?
then this is equivalent to
[ sec(x) - tan(x) ] x [ sec(x) + tan(x) ] = 1
let s evaluate it, we got
sec2(x) - sec(x)tan(x) + - sec(x)tan(x) - tan2(x) = sec2(x) - tan2(x)
= (1 - sin2(x) ) / cos2(x) = cos2(x) / cos2(x) = 1
as cos2(x) + sin2(x) = 1