What is is the ratio of the rise to the run of a line in a coordinate plane

Which expression gives you the distance between the points (5,1)and(9,-6)

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?

What is the measure of angle x? answer