,

Replace the variable with in the expression.

Remove parentheses.

Simplify the numerator.

One to any power is one.

Multiply by .

Subtract from .

Simplify the denominator.

One to any power is one.

Multiply by .

Add and .

Reduce the expression by cancelling the common factors.

Cancel the common factor of and .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Move the negative in front of the fraction.

Solve f(x)=(9x^2-25)/(9x^2+25) , f(1)