# Algebraic Expressions

# Distances and Speeds

Let *M* be miles, and let *K *be kilometers:

*K* = 1.609*M**M* = 0.6214*K*

Since (this is one of those important formulas you should probably commit to memory), in order to convert a speed from miles per hour (mph) to kilometers per hour (kph), we multiply by 1.609:

To convert a speed from kph to mph, we multiply by 0.6214.

### Sample Problem

A sign in Canada says "Speed Limit 100 kph (eh)." How fast is this speed in mph?

To convert a speed from kph to mph we multiply the speed by 0.6214. Therefore, 110 kph is 0.6214(110) = 68.354, or approximately 68 mph. That should be just fast enough to power your way through a moose.