The equation would be x+2x+1/2x=9 miles. Add all the like terms. x+2x=3x. 3x+1/2x= 3 1/2x. So 3 1/2x=9. Then you would have to do 3 1/2x divided by 3 1/2 which would equal x. Then, 9 divided by 3 1/2 which would equal about 2.57....not completely sure but try it...
Step-by-step explanation: You would think 15. 810 copies every 9, minutes. Nine divided by 810 equals 90. 90 copies every minute. 1,350 divided by 90 is fifteen. =fifteen.