Slope= rise/run= changes in y/changes in x = y2-y1/x2-x1 (find the differences and then divide) Remember it does not matter if y2-y1 or y1-y2, as long as you use the same order to set up y/2 ex. = -6-(-3)/2-(-4) = -9/6 or -3/2
"Rate of change" is a term that often is used to refer to the amount of change in a given time. Often, it is normalized to a particular unit of time.
A change of 4 ft in 2 hours, for example, might be said to be a rate of change of 2 ft per hour. Climate change is sometimes expressed in terms of the rate of change of sea level (so many centimeters per century) or average temperature at some location (so many degrees per century).
The term "rate of change" can also refer to changes that occur with respect to some other independent variable. A rate of elevation change, for example, is usually referred to a particular horizontal distance. An example of such a rate might be 1000 ft per mile.
If the units of the change and the corresponding independent variable are the same, then the rate of change can sometimes be conveniently expressed as a percentage. The rate of change of prices, for example, is often expressed this way. A price that goes up $0.10 on an item that was originally $1.00 is said to change by 10%. If that change occurs over a period of 5 years, then the rate of change might be expressed as 2% per year.