Which mixed number is equivalent to 21/13(−10/9+4)?

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.

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Marcus needs to rewrite f(x) = x2 + 6x + 4 in vertex form.