Which situation best fits the following equation? 7x -14 equals 21 a. alex is riding his bike to his grandmothers home 14 miles away. if he is gone 21 miles so far and is riding at a pace of 7 mph, how many more hours must he ride his bike? b. alex is riding his bike to his grandmothers house 21 miles away. if he is gone 14 miles so far and is riding at a pace of 7 mph, how many more hours must he ride his bike? c. alex is riding his bike to his grandmothers home 21 miles away. if he is gone 7 miles so far and is writing out a piece of 14 mph, how many more hours must he ride his bike? d. alex is riding his bike to his grandmothers home 14 miles away. if he has gone 7 miles so far and is riding at a pace of 21 mph, how many more hours must he ride his bike?