How would you describe the slice that created the triangular cross-section on this cake?
perpendicular to
the base
diagonal to the
base cutting off
exactly 1 vertex
parallel to
the base
diagonal to the
base cutting off
exactly 1 edge

the revenue of the fitness center, y, is the product of two factors: the number of members and the fee paid by each member. there are 320 members now, but number of members goes down by 10 for each $5 increase in fees, so if x is the number of $5 price increases then members is equal to (320 - 10x). since the fee is currently $45, and the fee increases by $5 for every price bump x, the fee is given by (45 + 5x). so, revenue y is given by y = (320 - 10x)(45 + 5x).

there were a lot of them but the first one to pop up on a google search was bts