What does the ratio pi represent in any circle?

The long jump record, in feet, at a particular school can be modeled by f(x) = 19.6 + 2.5ln(x + 1) where x is the number of years since records began to be kept at the school. what is the record for the long jump 11 years after record started being kept? round your answer to the nearest tenth.

If f(x) = 2x + 2 and g(x) = x? , what is (gºf)(2)?

How to solve a simultaneous equation involved with fractions?