Which is the direct linear variation equation for the relationship?

y varies directly with x and y = 12 when x = 4.

A.

y = 2x + 4

B.

y = 3x

C.

y = x + 8

D.

y = x - 8

The number of a checking account is also known as the

The price of a gallon of gasoline has increase, on average from $2.50 in 2006 to $4.00 in 2008. What is the percentage of increase?

A professor uses a video camera to record the motion of an object falling from a height of 250 meters. The function f (x) = - 5x2 + 250 can be used to represent the approximate height of the object off the ground after x seconds.

Johanna wrote the system of equations. 4 x - 3 y = 1, 5 x + 4 y = 9. If the second equation is multiplied by 4, what should the first equation be multiplied by to eliminate the x-variable by addition?

Find the mileage for a car that travels 576 miles on 18 gallons of gas.

A newspaper reporter wants to know how popular the hobby of bird watching is in the city. He asked people at the local bird refuge if they watched birds as a hobby. Which of the following best explains whether the reporters data is valid or not?

I am very confused on how to figure out if y = 3/4x is proportional?

Alison wants to buy a mountain bike for $339.12. If she saves $28.26 each month, in how many months will she be able to buy the bike?

At 12 o'clock the temperature was 7°C. The temperature decreased by - 20°C. What is the new temperature?

Ashleys rentals charges $27.50 per hour to rent a surfboard and a wetsuit. Darlas surf shop charges $23.25 per hour to rent a surfboard plus $17 extra for a wetsuit.