Question

Derrick and Mark are brothers who live in the same house. Mark is home, and Derrick is 5 mi from home. Both boys begin riding their bikes at the same time. Derrick rides directly home at a constant rate of 15 mph, and Mark rides away from home at a constant rate of 18 mph.

Let d represent distance from home, and let t represent time in hours.

Which system models this situation?


A.
d = 5 − 15t
d = 18t

B.
d = 15 − 5t
d = 18t

C.
d = 5 + 15t
d = 18t

D.
d = 5 − 15t
d = 5 + 18t

Answer 1

A

Answer 2

Was A right?