## Intermediate Algebra (12th Edition)

According to the quotient rule for exponents, $\frac{a^{m}}{ a^{n}}=a^{m-n}$. Therefore, our friend’s answer is incorrect because it divides the bases by each other, instead of just taking the difference of the exponents attached to the bases. In general, the quotient rule for exponents can only be used when the denominator and numerator have the same base. In this case, we cannot use any rule of exponents to simplify further.