How to solve this equation 2xsquare-4x-6=0

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

Which equation matches the graph shown ?

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.