How do you factor #25x^2-81#?
The answer is:
You first move the
We then get the square root of both sides of the equation.
The square roots are:
Applying this to our equation makes it like this.
We divide both sides by 5
This cancels both 5 on the
And we reach our answer:
When you see the numbers 25 and 81, you should realise that we will most probably be using the Sum or Difference of Squares Identities.
As there is a negative sign, we will use the Difference of Squares Identity
We can write the expression as