298 algebra De mystif ieD
PRACTICE- Terry, a marathon runner, ran from her house to the high school then back.
The return trip took 5 minutes longer. If her speed was 10 mph to the high
school and 9 mph back, how far is Terry’s house from the high school? - Because of heavy morning traffic, Toni spent 18 minutes more driving
to work than driving home. If she averaged 30 mph on her drive to
work and 45 mph on her drive home, how far is her home from her
work? - Leo walked his grandson to school. If he averaged 3 mph on the way to
school and 5 mph on his way home, and if it took 16 minutes long to
get to school, how far is it between his home and his grandson’s
school?
✔SOLUTIONS
- Let t represent the number of hours spent running from home to school.
Then t + ^5
60
represents the number of hours spent running from school
to home. The distance to school is given byd = 10t, and the distance
home is given by dt = () 605. + 910 9 5
6010 9 1
12
10 9 9
12
10 9ttttttt=+
=+
=+= tt
ttt+
−−=3
4
99
3
4The distance between home and school is 10 t = (^10) ()^34 = ^152 = 721 miles.
- Let t represent the number of hours Toni spent driving to work. Then
t – ^1860 represents the number of hours driving home. The distance from
PRACTICE- Terry, a marathon runner, ran from her house to the high school then back.