Whats the rate of change

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

Asap its important using the information in the customer order, determine the length and width of the garden. enter the dimensions.length: feetwidth: feet

The function v(r)=4/3pir^3 can be used to find the volume of air inside a basketball given its radius. what does v(r) represent