I need hlp with this math question I don't get it...

7. if the value of x varies directly with the value of y, and x = 3 when y = 21. what is the valu y, and x = 3 when y = 21. what is the value of x when y = 105?

Subscriptions to a popular fashion magazine have gone down by a consistent percentage each year and can be modeled by the function y = 42,000(0.96)t. what does the value 42,000 represent in the function?

The length of the shadow of a building is 120 meters, as shown below: building shadow 120 m what is the height of the building? (1 point)