How to factor our the coefficient of 9a-8?

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

Meghan has created a diagram of her city with her house, school, store, and gym identified. a. how far is it from the gym to the store? b. meghan also wants to walk to get some exercise, rather than going to the gym. she decides to walk along arc ab. how far will she walk? round to 3 decimal places.

The value of the expression 16-^3/4 8 1/8 -6 6 1/40 1/64