Question

81x2-1

Answer 1

do u want to factor this?

Answer 2

you would have to be able to identify this as difference of two squares...
you would have to know that for difference of two squares,
\[\large a^2-b^2=(a+b)(a-b)\]

Answer 3

http://sketchtoy.com/37128277
hope you can continue from there..

Answer 4

if we rewrite the question, \[\large (81x^2-1^2)\] what is our a? what is our b?

Answer 5

Simplifying
81x2 + -1 = 0

Reorder the terms:
-1 + 81x2 = 0

Solving
-1 + 81x2 = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '1' to each side of the equation.
-1 + 1 + 81x2 = 0 + 1

Combine like terms: -1 + 1 = 0
0 + 81x2 = 0 + 1
81x2 = 0 + 1

Combine like terms: 0 + 1 = 1
81x2 = 1

Divide each side by '81'.
x2 = 0.01234567901

Simplifying
x2 = 0.01234567901

Take the square root of each side:
x = {-0.111111111, 0.111111111}