How to determine if an equation is linear or not?

At time x= 0, water begins to drip steadily out of a water tank. After 4 hours, there are 5.6 gallons of water in the tank. After 6 hours, 5.4 gallons remain.

Using the equation for the line of the best fit, what is a good approximation for x when f (x) is equal to 30

Olivia is cutting a 1 1/2 m by 3/4 m piece of rectangular paper into two pieces along its diagonal. Find the area

What is the quotient of 36 divided by 4

Robin spent $17 at an amusement park for admissions and rides. If she paid five dollars for a mission and rides cost three dollars each what is the total number of rides that she went on

Anton has 4 pennies, 1 dime, and 2 dollar bills. He buys a granola bar for $0.89. How much money does he have left? ones, tenths, hundredths

An expression is written as m-5 (m+3) + 7m. What is the value of the expression when m=x+1?

Cormac is making 29 phone calls each week as part of a fundraiser. Last week, he made 10 phone calls on weekdays. Which equation could be used to find x, the number of phone calls he made last week on weekend days?

Jasmin's dog weighs 58 pounds. Her vet told her that a healthy weight for her dog would be less than or equal to 40 pounds. Jasmin's dog can lose an average of 1.5 pounds every week.

A town with an initial population of 2,000 doubling in size every 10 years. Exponential function or no?