What are the answers in chapter 3 math book for 5th grade?

The line containing the midpoints of the legs of right triangle abc where a(-5,5), b(1, 1), and c(3, 4) are the vertices.

The larger of two number is 4 less than twice the smaller number. the sum is 41. find the numbers

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?