Answer:
an equation that relates x and y :
y = 1.125x
Step-by-step explanation:
The direct variation says that:

then equation is of the form:
where k is the constant of variation.
As per the statement:
The variables x and y vary directly.
then by definition we have;
.....[1]
Given that: y = 45 and x = 40
Substitute these in [1] to solve for k;

Divide both sides by 40 we have;

Therefore, an equation that relates x and y :
y = 1.125x