Toby rides his bike to school every day and to his best friend's house regularly. One week, he rode to and from school 5 times and to and from his best friend's house 3 times. He rode a total of 14.4 miles that week. The next week, he rode to and from school 4 times and to and from his best friend's house 6 times . He rode a total of 14.4 miles that week, too. This system of equations can be used to represent the situation : 5x + 3y = 14.4; 4x + 6y = 14.4