To simplify this expression would be 4x-3
Inverse Property, I am pretty sure. Not sure though.
Answer: 3 mi/h
Step-by-step explanation:
Here we have to find the speed
at which Sarah walks to school, knowing the distance
she has walked and the time
she expends.
So, in this case we can use the following equation:

Where:


Solving:

This is Sarah's speed