Question 392689
Distance(d) equals Rate(r) times Time(t) or d=rt; r=d/t and t=d/r
Let r=rate of first cyclist
Then r+4=rate of other cyclist

In 4 hours, first cyclist travels 4r miles
In 4 hours, other cyclist travels 4(r+4) miles
And we are told that these two distances add up to 112 miles, sooooo:
4r+4(r+4)=112
4r+4r+16=112 subtract 16 from both sides
8r=112-16
8r=96
r=12 mph----rate of first cyclist
r+14=12+4=16 mph--rate of other cyclist
CK
In 4 hours, first cyclist travels 4*12=48 mi
In 4 hours other cyclist travels 4*16=64 mi
64+48=112
112=112
Hope this helps---ptaylor