Which shows all the values of a that make the rational expression a = 9 a = 3 a = –9 or a = 9 a = –3 or a = 3

The spotter on the ground is standing beneath the safety net. what is his distance from the base of the platform, to the nearest meter? 3 meters, 2 meters, 4 meters, 1 meter?

Answer this question, only if you know the answer. 30 points and brainliest!

Simplify the expression. -2/5(10+15m-20n)