Malory rode her bicycle 54 miles in 4.5 hours , at the rate how far can she ride in 6 hours

First, we divide 54 by 4.5 to find out how many miles she can ride in 1 hour, then multiply that to 6 to find how many miles she can ride in 6 hours. 54 / 4.5 = 12, and 12 x 6 = 72, so she can ride 72 miles in 6 hours. :)

You have to divide 54 by 4.5 to get the rate per hour then you times that by six and you get 72 so it would look like this 
54/4.5=12*6= 72 so your answer would be 72