What is the solution to this equation?
4x - 6 + 2 x = 18

x = 4

Step-by-step explanation:

4x - 6 + 2x = 18

4x + 2x = 18 + 6                 collect like terms

6x = 24                              divide both sides by the coefficient of x

x = 4

16 times

Step-by-step explanation:

Since he has a 4-gallon aquarium and a 1-quart container, and since there are 4 quarts in every gallon, he'll need to fill the aquarium with the container full 16 times because for every gallon, he'll need to fill the aquarium 4 times. This is the equation:

4*4=16 times