Posted by jordan on Thursday, October 15, 2009 at 1:18pm.
Yesterday Lucy walked 2 hours and jogged 1/2 hour and covered 6.25 miles. Today she walked for 3 hours and jogged for 1 hour and covered 10.25 miles. Assuming a constant walking rate and a constant jogging rate, how fast did she walk and how fast did she jog? Define two variables, write a system of equations, and solve to find the walking rate and the jogging rate. Justify your answer by showing how you solved the problem.
w walking j jogging
2w + .5j= 6.25 > 3(2w+.5j)= 3(6.25)
3w + 1j= 10.25 > 2(3w+1j)= 2(10.25
6w + 1.5j= 18.75>> .5j=1.75
6w  2j= 20.50 >> j=.3
2w + .5(.3)= 6.25
2w + 15= 6.25
2w= 6.10 w= 3.05
check:
2(3.05) + .5(.3)= 6.25 (correct)
3(3.05) + 1(.3)= 9.45(wrong!!) it should be 10.25.

algebra...redo.  MathMate, Thursday, October 15, 2009 at 3:22pm
Up to this line, things are OK.
6w  2j= 20.50 >> j=.35
Could you continue and check?