A student performed the following steps to find the solution to the equation. where did he go wrong?

I'm terrible at math any here is appreciated.

The speed of a falling object increases at a constant rate as time increases since the object was dropped. which graph could represent the relationship betweent time in seconds, and s, speed in meters per second? speed of a falling object object over time

Which polynomial function has x intercepts -1, 0, and 2 and passes through the point (1, -6)