Answer:
There are 18 fish in the fish tank.
Step-by-step explanation:
The volume of a fish tank is 60 cubic feet: V = 60 ft³.
The density is 0.3 fish over feet cubed. d = 0.3 fish/ft³
We can find the number of fish using proportions. The required conversion factor is 0.3 fish/ft³. The number of fish is:
60 ft³ × (0.3 fish/ft³) = 18 fish
There are 18 fish in the fish tank.
Use the substitution method
use the first equation, let y = k - x
plug y = k - x into the second equation
==> 2x + 3(k - x) = k + 1
==> 2x + 3k - 3x = k + 1
==> -x = k - 3k + 1
==> -x = -2k + 1
==> x = 2k - 1 is the answer
If 1 mile = 1.609 km then we can use it as the conversion factor in the following way, remembering that the equation has to be set so that the miles cancel with miles.
4.5 miles =

⇒ 7.2405 km