Lucy earns money babysitting. her earnings and hours worked represent a direct variation. she worked for 4 hours and earned $25.
determine the constant of proportionality for dollars earned per hour worked
determine the constant of proportionality for hours worked per dollar earned.

For this case we have that by definition, a direct variation is given in the form:

Where:

k: It is the constant of proportionality

According to the statement we have to:

Substituting:

On the other hand we have:

answer: d. $20

step-by-step explanation:

just took the test

i believe it is c.y = 9x

rise over run. 9 units up over 1 unit right or 9/1