3y+12=-48 what does y equal? ( show work)

-3y +12 = -48

subtract 12 from both sides:

-3y = -60

divide both sides by -3

y = -60 / -3 = 20

y = 20

m∠a is 90°

m∠b is 40°

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).