Question

81x^2-1

Answer 1

What about it?

Answer 2

difference of 2 squares
to factor use the identity

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

Answer 3

@ashleyamber123
can you figure out what could you take 'a' as here ? and 'b' as ?
81x^2-1 = (9x)^2-(1)^1 >>>>>>of the form a^2-b^2
a^2 - b^2 = (a - b)(a + b)

Answer 4

you need the square root of 81x^2
and square root of 1
and take the first as 'a' and second as 'b' as hartnn said

Answer 5

the fit them into (a - b)(a + b)

Answer 6

I figured it out, the answer was (9x-1)(9x+1)

Answer 7

right

Answer 8

thank you all :)

Answer 9

yes, thats correct, but could you do similar problems on your own?

Answer 10

I was confused because the assignment is for trinomials and that wasn't a trinomial.

Answer 11

$$81x^2-1=81x^2+0x-1$$

Answer 12

a quadratic expression can always be expressed as trinomial :)