An item on sale costs 20% of the original price. If the original price was $50, what is the sale price?

Sale Price: $40

Step-by-step explanation:

This means the cost of the item to you is $40. You will pay $40 for a item with original price of $50 when discounted 20%. In this example, if you buy an item at $50 with 20% discount, you will pay 50 - 10 = 40 dollars.

4

6 cm

step-by-step explanation:

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).