Question 969617
W=time walking; J=time jogging
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W+J=0.9hr
W=0.9hr-J Use this below to substitute for W.
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3mph(W)+5mph(J)=3.5 miles Substitute for W from above.
3mph(0.9hr-J)+5mph(J)=3.5 miles
2.7 miles-3mph(J)+5mph(J)=3.5 miles Subtract 2.7 miles from each side.
2mph(J)=0.8 miles Divide each side by 2mph.
J=0.4 hr
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ANSWER 1: Jim jogged for 0.4 hour.
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W=0.9hr-J=0.9hr-0.4hr=0.5hr
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ANSWER 2: Jim walked 0.5 hour.
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CHECK:
3mph(W)+5mph(J)=3.5 miles
3mph(0.5hr)+5mph(0.4hr)=3.5 miles
1.5 miles + 2 miles=3.5 miles
3.5 miles=3.5 miles