Find two pairs of integers whose product is -20

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?

Can someone me find the original price? the discount is 5% and the sale price is $68.40

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?