hi please explain work! Also for part a solve without using K please. thank you!

15-4 A +2 percent grade intersects with a -1 percent grade at station (535+24.25) at an eleva- tion of 300 ft. If the design speed is 65 mi/h, determine: (a) the minimum length of vertical curve using the rate of vertical curvature Then, using the length found in part (a), find: (b) the stations and elevations of the BVC and EVC (c) the elevation of each 100-ft station (d) the station and elevation of the highpoint