Respuesta :
d = 11c
d + c = 156
11c + c = 156
12c = 156
c = 156/12
c = 13
d = 11c
d = 11(13)
d = 143 <== she biked 143 miles
d + c = 156
11c + c = 156
12c = 156
c = 156/12
c = 13
d = 11c
d = 11(13)
d = 143 <== she biked 143 miles