Please help there was a loss of$ 6 on my investment over one and third months based on this what was the investment average dollar amount change per month

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

Aiden drives to school and back each day. the school is 16 miles from his home. he averages 40 miles per hour on his way to school. if his trip takes 1 hour, at approximately what speed does aiden drive home?

Just tell me how to set up the equation.