What is the gradient when y=0​

Rewrite the following quadratic functions in intercept or factored form. show your work. y = 5x^2 + 10x

David and alton are training for a race. they spend 35 minutes stretching and then go on a 5 mile practice run. david runs at a pace of 7 min/mile. alton runs at a pace of 8 min/mile. write an equation for each runner that shows the total length of their workout. then solve each equation showing your work

Factor these polynomials and explain how 1. 12x - 3x^2 2. 20 - 240x^2