# Thread: Having a problem with a negative exponet problem

1. ## Having a problem with a negative exponet problem

Where am I going wrong it should equal 2r^3/3
TIA

2. You are wrong at the first step.
$4r^{-3}=\frac{4}{r^3}$ and $6r^{-6}=\frac{6}{r^6}$

3. thanks.