To simplify the expression, we first recognize that dividing by a fraction is equivalent to multiplying by its reciprocal
step 2
The reciprocal of x+91 is x+9
step 3
We multiply the numerator (x2−81) by the reciprocal of the denominator (x+9)
step 4
The expression simplifies to (x2−81)(x+9)
step 5
We expand the expression to get x3+9x2−81x−729
Answer
x3+9x2−81x−729
Key Concept
Dividing by a fraction is equivalent to multiplying by its reciprocal.
Explanation
To simplify a complex fraction, we can multiply the numerator by the reciprocal of the denominator. This eliminates the complex fraction and allows us to simplify the expression further.