What letter represents the initial value in y=a(b)^x

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

What is the answer to this question? i'm a bit stumped. also how do i do it? 5(x - 4) = 2(x + 5)

Consider a cube that has sides of length l. now consider putting the largest sphere you can inside this cube without any point on the sphere lying outside of the cube. the volume ratio -volume of the sphere/ volume of the cube is 1. 5.2 × 10−1 2. 3.8 × 10−1 3. 1.9 4. 2.5 × 10−1 5. 3.8