Phoenix hiked the Rocky Path Trail last week. It took four days to complete the trip. The first two days she hiked a total of 22 miles. The second and third days she averaged 18 miles per day. The last two days she hiked a total of 30 miles. The total hike for the first and third days was 26 miles. How many miles long was the trail?
Let the miles she walked on the first day be a, miles walked on the second day be b, and so on.
first 2 days, she hiked a total of 22 miles ==> a + b = 22
2nd and 3rd days, averaged 18 mi/day ==> (b + c)/2 = 36
last two days, hiked total of 30 miles ==> c + d = 30
first and third days ==> a + c = 26
We have four equations and four variables, so we can solve. I hope this gets you started.