document.write( "Question 145407: A ladder is leaning against a wall. The distance from the bottom of the ladder to the wall is 3 feet less than the length of the ladder. Find the length of the ladder, if the distance of its top to the ground is 4 feet less than the length of the ladder. \n" ); document.write( "
Algebra.Com's Answer #106086 by ankor@dixie-net.com(22740) You can put this solution on YOUR website! A ladder is leaning against a wall. The distance from the bottom of the ladder to the wall is 3 feet less than the length of the ladder. Find the length of the ladder, if the distance of its top to the ground is 4 feet less than the length of the ladder. \n" ); document.write( ": \n" ); document.write( "Using the formula a^2 + b^2 = c^2 \n" ); document.write( ": \n" ); document.write( "Let x = length of the ladder (c) \n" ); document.write( ": \n" ); document.write( "\"The distance from the bottom of the ladder to the wall is 3 feet less than the length of the ladder.\" Therefore: \n" ); document.write( "(x-3) = a \n" ); document.write( ": \n" ); document.write( "\"the distance of its top to the ground is 4 feet less than the length of the ladder.\" therefore: \n" ); document.write( "(x-4) = b \n" ); document.write( ": \n" ); document.write( "Using the formula we have: \n" ); document.write( "(x-3)^2 + (x-4)^2 = x^2 \n" ); document.write( "FOIL \n" ); document.write( "(x^2 - 6x + 9) + (x^2 - 8x + 16) = x^2 \n" ); document.write( ": \n" ); document.write( "Combine like terms on the left \n" ); document.write( "x^2 + x^2 - x^2 - 6x - 8x + 9 + 16 = 0 \n" ); document.write( ": \n" ); document.write( "x^2 - 14x + 25 = 0 \n" ); document.write( ": \n" ); document.write( "Solve for x using the quadratic formula; \n" ); document.write( " \n" ); document.write( " a=1; b=-14; c=25 \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "you can do the math here, the reasonable solution is x = 11.9' length of ladder \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check solution \n" ); document.write( "8.9^2 + 7.9^2 = 141.6 which is 11.9 squared\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |