Help me solve this problem

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?

4. bob solved the inequality problem below incorrectly. explain his error and redo the problem showing the correct answer. ? 2x + 5 < 17 ? 2x + 5-5 < 17-5 -2x/-2 < 12/-2 x < -6