document.write( "Question 293835: A man walks a certain distance at a certain speed. Had he walked 1/2 km / hr faster, he would have taken one hour less. But if he had walked 1 km /hour slower, he would have taken 3 hours longer. the distance travelled by him is ? \n" ); document.write( "
Algebra.Com's Answer #212055 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! A man walks a certain distance at a certain speed. \n" ); document.write( " Had he walked 1/2 km / hr faster, he would have taken one hour less. \n" ); document.write( " But if he had walked 1 km /hour slower, he would have taken 3 hours longer. \n" ); document.write( " The distance traveled by him is: \n" ); document.write( ": \n" ); document.write( "Let r = the rate the man walked \n" ); document.write( "then \n" ); document.write( "(r+.5) = 1 hr less rate \n" ); document.write( "and \n" ); document.write( "(r-1) = 3 hr more rate \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "let t = time he actually walked \n" ); document.write( "then \n" ); document.write( "(t-1) = time at the faster rate \n" ); document.write( "and \n" ); document.write( "(t+3) = time at the slower rate \n" ); document.write( ": \n" ); document.write( "distance for all three situations is the same (dist = rate * time): \n" ); document.write( "; \n" ); document.write( "actual dist = faster time dist \n" ); document.write( "rt = (r+.5)(t-1) \n" ); document.write( "rt = rt - r + .5t - .5 \n" ); document.write( "rt - rt + r - .5t = -.5 \n" ); document.write( "r - .5t = -.5 \n" ); document.write( ": \n" ); document.write( "actual dist = slower time dist \n" ); document.write( "rt = (r-1)(t+3) \n" ); document.write( "rt = rt + 3r -t - 3 \n" ); document.write( "rt - rt - 3r + t = -3 \n" ); document.write( "-3r + t = -3 \n" ); document.write( ": \n" ); document.write( "multiply the 1st equation by 2 and add to the above equation \n" ); document.write( "2r - t = -1 \n" ); document.write( "-3r + t = -3 \n" ); document.write( "---------------eliminates t \n" ); document.write( "-r = -4 \n" ); document.write( "r = 4 km/h is the actual walking rate \n" ); document.write( ": \n" ); document.write( "Find t using: r -.5t = -.5 \n" ); document.write( "4 - .5t = -.5 \n" ); document.write( "-.5t = -.5 - 4 \n" ); document.write( "-.5t = - 4.5 \n" ); document.write( "Multiply eq by -2 \n" ); document.write( "t = 9 hrs actual time \n" ); document.write( ": \n" ); document.write( "Dist = r*t \n" ); document.write( "4 * 9 = 36 km \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "see if this is true; find the time of each scenario \n" ); document.write( "36/4.5 = 8 hrs (1h less) \n" ); document.write( "36/3 = 12 hrs (3hr more) \n" ); document.write( " \n" ); document.write( " |