Explanation on linear equations

The area a equals pi R squared of a circular water ripple changes with the radius. At what rate does the area change with respect to the radius when r equals 4

A resturant charges an automatic 20% tip for groups of 6 or more. A group of 8 people had a bill of $187. How much was their tip?

Which expression is equivalent to am : an?

Daniel borrowed $5000 from the bank for 2 years at 9% simple interest per annum. Calculate how much interest Daniel is charged.

The amount of radioactive uranium changes with time. The table below shows the amount of radioactive uranium f (t) left after time t: t (hours) 0 0.

The degree of the function f (x) = - (x + 1) 2 (2x - 3) (x + 2) 2 is and its y-interceptis

11. John walked 10 miles on Saturday. He walked twice as fast on the second 5 miles of his walk than he walked on the first 5 miles of his walk.

Which coins have a diameter with a 5 in the hundredths place

There are 9 1/5 and people ate 6 2/3 how much is left

Gabe has already spent 2 minutes on the phone, and he expects to spend 1 more minute with every phone call he routes. In all, how many phone calls does Gabe have to route to spend a total of 37 minutes on the phone?