What does -4x + 9x equals

Angela rode his bike around a bike trail that was 1/4 of a mile long he rode his bike around the trail 8 * angelo says he wrote a total of 8/4 miles to russell says he's wrong and he actually and says that he actually wrote to my who is corrupt use words and trying to explain how you know.

What is the rate of change of a line that passes through (2,-5) and (6,-2)?

Use sigma notation to represent the following series for 9 terms.