Real fourth roots of -625

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

Bring the fraction a/a-4 to a denominator of 16-a^2

Which of the following is closest to 32.9 x 7.5? a: 232 b: 259 c: 220 d: 265