Let r1 and r2 be the "divides" and "is a multiple of" relations on the set of all positive integers, respectively. thatis, r1 ={(a, b)|adividesb}andr2 ={(a, b)|a is a multiple of b}. find

a. r1 ∪r2.

b. r1 ∩r2.

c. r1 −r2. d)r2−r1. e)r ⊕r. 1 2

Desmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? 8,000 + 24x 8,000 − 24x 8,000 + 2x 8,000 − 2x

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.

David estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x. create a question you could ask that could be answered only by graphing or using a logarithm.