To write an equation that represents a proportional relationship between two quantities, we need to know either the constant of proportionality or two corresponding values of the quantities.
For example, if we know that the relationship between the number of hours worked and the amount earned is proportional, and we are given that for every 2 hours worked, $30 is earned, we can write the equation as follows:
Amount earned = constant of proportionality ร hours worked
Let's denote the constant of proportionality as k. In this case, we have:
Amount earned = k ร hours worked
We are given that for every 2 hours worked, $30 is earned. So we can substitute these values into the equation:
$30 = k ร 2
Simplifying the equation:
k ร 2 = $30
We can solve for k by dividing both sides of the equation by 2:
k = $30 รท 2
k = $15
Thus, the equation that represents the relationship between the number of hours worked (h) and the amount earned (a) is:
a = 15h