document.write( "Question 720992: If a piece of wood is 5cm longer than a second piece and 3 divide by 4 of the second piece is equal to 3 divide 5 of the first.What is length of second piece \n" ); document.write( "
Algebra.Com's Answer #442126 by DrBeeee(684)\"\" \"About 
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Always define a variable for the unknowns.
\n" ); document.write( "Let x = the length of the first piece of wood
\n" ); document.write( "Let y = the second piece of wood
\n" ); document.write( "Now you need TWO equations to find two unknowns.
\n" ); document.write( "The first part of the problem statement gives us
\n" ); document.write( "(1) x = y + 5.
\n" ); document.write( "The second part gives us
\n" ); document.write( "(2) (3/4)*y = (3/5)*x
\n" ); document.write( "Solve these two equations for (x,y). You can use any of the known methods, I'll use substitution for you.
\n" ); document.write( "Substitute the expression for x given by (1) into (2) and get
\n" ); document.write( "(3) (3/4)*y = (3/5)*(y + 5) or
\n" ); document.write( "(4) (3/4)*y = (3/5)*y + (3/5)*5 or
\n" ); document.write( "(5) [(3/4) - (3/5)]*y = 3 or
\n" ); document.write( "(6) [(15 - 12)/20]*y = 3 or
\n" ); document.write( "(7) (3/20)*y = 3 or
\n" ); document.write( "(8) y = 20
\n" ); document.write( "Now put y of (8) into (1) and get
\n" ); document.write( "(9) x = 20 + 5 or
\n" ); document.write( "(10) x = 25
\n" ); document.write( "Let's check these two values using (2).
\n" ); document.write( "Is ((3/4)*20 = (3/5)*25)?
\n" ); document.write( "Is (15 = 15)? Yes
\n" ); document.write( "Answer: The first piece of wood is 25cm and the second piece is 20cm. \n" ); document.write( "
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