What is constant of proportionality?

The table shows the balance of a money market account over time. write a function that represents the balance y (in dollars) after t years.

One positive number is 9 more than twice another. if their product is 95, find the numbers

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field