Question 170955
ok.......this isnt written very well but what they are getting at is she walked a portion and jogged a portion of the trip(8km) to school. d=rt.  lets call the distance she walked x and the distance she jogged 8-x. lets the time she walked t and the time she jogged 1-t(1hour altogether). walking rate is 5 and jogging rate is 9
:
x=5t.........eq 1
8-x=9(1-t)...eq 2
:
take x's value from eq 1 and plug it into eq 2
:
8-5t=9(1-t)
:
8-5t=9-9t
:
4t=1
:
{{{t=1/4}}}hour she walked
:
we are after distance she jogged so lets find x ...x=5(1/4)=5/4=1.25..distance she walked
:
distance she jogged is 8-x...{{{highlight(8-(1.25)=6.75)}}}km