(a) There is a direct correlation that the students who spent more hours on homework earned a better test score.
(b) 64 test score.
Plug 3 as 'x' into 8x + 40. You have 8 × 3 + 24, which is 64.
(c) The number 40 in the equation means that without any time spent on homework, a student will likely earn a minimum of 40 score.
Hope that helps!
:D®