Looks good to me.
I tend to avoid fractions where possible, so I'd probably have done it as
42+48+x = 3*47
Tom went on a 3 Day road trip in which he drove the same number of miles each day. He drove 42 mph the first day. He drove 48 mph the second day. On the last day he drove a x mph. His average speed for the whole trip was 47 mph. Find x and write your answer to the nearest hundredth.
I added (42+48+x) divided by three equals 47 and got x = 51 mph
2 answers
Perry goes for a 4-hour trip through towns and on country roads. If she averages 65 mph on country roads and 25 mph through towns, and she travels three times as far on country roads as she does through towns, what is the total length of her trips?