A.) As the number of hours spent on homework increases, the test scores received also most likely will increase.
B.) If someone does 2 hours of homework, you just sub in 2 for x, so you should get the equation y=8(2)+40, or a score of 56.
C.) The 40 is the y intercept, which means that the student is guaranteed to get at least a 40 on a test even if they study for 0 hours.
Hope this helps :)