Describe methods you can use to show a proportional relationship between two variables, x and y. for each method, explain how you can find the unit rate and the slope.

If the ratio of x/y or x/y is always the same constant, then a and y are directly proportional and the constant is called the constant of proportionality. 

If the product of xy is always the same constant, then a and y are inversely proportional and the constant is called the constant of proportionality. 

unit rates --- are like any rate found by dividing --- like speed --- miles per hour unit means 1 and this is miles traveled in one hour (at constant speed) --- so you just divide --- traveling 100 miles in 2 hours = 50 miles in 1 hour --- 50 miles per hour --- miles/hour <<< that is a unit rate 

slope is a rate of change --- on an x-y coordinate axis graph the slope is the rate of change of y compared to a change in x --- this is not necessarily a unit rate ... slope of 2/3 means a change of 2 for y will create a change of 3 for x (not a change of 1, so it is not a unit rate)