Problem:
given y varies directly with x, write the equation that relates x and y. find k first
x = 1/6 , y = 1
Solution.
A proportional relationship between two variables x and y is given by:
y = kx
where k is the proportionality constant.
Now, if x = 1/6 and y = 1 replacing these values in the previous equation we obtain:

solving for k:

then, we can conclude that the equation that relates x and y is:
