Question

factor 4 − x2

Answer 1

\(a^2-b^2 = (a-b)(a+b)\)
you have

\(2^2-x^2\) so ?

Answer 2

i understand the first part you have but not the second

Answer 3

so for you \(a=2, b = x\)

so what is \((a-b)(a+b)\)?

Answer 4

\((a+b)(a-b)\)

\(\uparrow\) put a 2 where you see an \(a\), put a \(x\) where you see a \(b\).

Answer 5

I am sapopse to be factoring but you cant use the equation a^2 + b^2 = (a + b)(a - b) because the four is positive and the x^2 is negative

Answer 6

\(4-x^2=2^2-x^2=(2-x)(2+x)\)

Answer 7

wait but that means i could factor out a -1 right then the equation becomes -1(X^2 - 4)

Answer 8

you have that equation wrong

its not
\(a^2 + b^2 = (a + b)(a - b) \)

its

\(a^2 - b^2 = (a + b)(a - b) \)

Answer 9

ok ya well thats what i ment and i see what you are implying now but idk how it will help me factor

Answer 10

Take the square root of 4 and x^2. (2 - x)^2 = (2 + x)(2 - x). FOIL this out and you should get: 4 - 2x + 2x - x^2 --> 4 - x^2. That factored form of 4 - x^2 is (2 - x)^2.

This applies to numbers like 10^2 - 15^2. (10 + 15)(10 - 15) = 25*-5 = -125