Two high-speed ferries leave at the same time from a city to go to the same island. The first ferry, the Cat, travels at 28 miles per hour. The second ferry, the Bird, travels at 21 miles per hour. In how many hours will the two ferries be 7 miles apart?

step-by-step explanation:

i dont get

hello from mrbilldoesmath!

answer:

the domain is the set { -2, 0, 2, 3}

discussion:

the domain is the set of x values in the ordered pairs (x,y). taking the x, or first component, of each ordered pair gives   -2, 0, 2, 3.

you,

mrb

c

-by-step explanation:

it would be c