What is the gradient line of 45 degree that makes with positive x ais​

Elena and her husband marc both drive to work. elena's car has a current mileage (total distance driven) of 15,000 and she drives 23,000 miles more each year. marc's car has a current mileage of 46,000 and he drives 9,000 miles more each year. will the mileages for the two cars ever be equal? explain.

Thelime contains the point(-3,0) and parallel x-3y=3( show all work)

With alll of except for the 2 that i did already