document.write( "Question 161592: 1. find three consecutive even integers whose sum is 42.
\n" ); document.write( "2. the difference of the squares of the digits of a two digit positive number is
\n" ); document.write( " 27. If the digits are reversed in order and the resulting number is subtracted
\n" ); document.write( " from the original number, the difference is also 27.what is the original
\n" ); document.write( " number?
\n" ); document.write( "3.A's rate of doing work is three times of B. On a given day, A & B work together
\n" ); document.write( " for 4 hrs.;B is called away and S finishes the rest of the job in 2 hrs. How
\n" ); document.write( " long would it take B to do the complete job alone?
\n" ); document.write( "4.Peter can run around a 400m tract in 65 sec. How long does it take for John to
\n" ); document.write( " run the 400m if he meets Peter in 35 sec.After they start together in a race
\n" ); document.write( " around the tract in opposite direction?
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Algebra.Com's Answer #119143 by ankor@dixie-net.com(22740)\"\" \"About 
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1. find three consecutive even integers whose sum is 42.
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\n" ); document.write( "x + (x+2) + (x+4) = 42
\n" ); document.write( "3x + 6 = 42
\n" ); document.write( "3x = 42 - y
\n" ); document.write( "3x = 36
\n" ); document.write( "x = 12
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\n" ); document.write( "2. The difference of the squares of the digits of a two digit positive number
\n" ); document.write( " is 27. If the digits are reversed in order and the resulting number is
\n" ); document.write( " subtracted from the original number, the difference is also 27.
\n" ); document.write( " what is the original number?
\n" ); document.write( ":
\n" ); document.write( "Let the number = 10x + y
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\n" ); document.write( "\"The difference of the squares of the digits of a two digit positive number
\n" ); document.write( " is 27.
\n" ); document.write( "y^2 - x^2 = 27
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\n" ); document.write( "\"If the digits are reversed in order and the resulting number is
\n" ); document.write( " subtracted from the original number, the difference is also 27.\"
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\n" ); document.write( "10y + x - (10x + y) = 27
\n" ); document.write( "10y + x - 10x - y = 27
\n" ); document.write( "10y - y - 10 + x = 27
\n" ); document.write( "9y - 9x = 27
\n" ); document.write( "Simplify, divide equation by 9
\n" ); document.write( "y - x = 3
\n" ); document.write( "y = (x + 3)
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\n" ); document.write( "Substitute this for y in the 1st equation, find x
\n" ); document.write( "(x+3)^2 - x^2 = 27
\n" ); document.write( "(x^2 + 6x + 9) - x^2 = 27
\n" ); document.write( "x^2 - x^2 + 6x + 9 = 27
\n" ); document.write( "6x = 27 - 9
\n" ); document.write( "6x = 18
\n" ); document.write( "x = 3
\n" ); document.write( "Then
\n" ); document.write( "y = 3 + 3
\n" ); document.write( "y = 6
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\n" ); document.write( "Our number is 36; Check it: 63 - 36 = 27
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\n" ); document.write( "3. A's rate of doing work is three times of B. On a given day, A & B work
\n" ); document.write( " together for 4 hrs; B is called away and S finishes the rest of the job
\n" ); document.write( " in 2 hrs. How long would it take B to do the complete job alone?
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\n" ); document.write( "Where did S come from (a relative perhaps?) I assume you mean A.
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\n" ); document.write( "Let x = time required by A to do the job alone
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\n" ); document.write( "Let 3x = time required for B to do the job alone. (works 1/3 as fast as A)
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\n" ); document.write( "Let the completed job = 1
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\n" ); document.write( "The given information tells that A worked 6 hrs, and B worked 4 hrs:
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\n" ); document.write( "\"6%2Fx\" + \"4%2F%283x%29\" = 1
\n" ); document.write( "Multiply equation by 3x, results
\n" ); document.write( "3(6) + 4 = 3x
\n" ); document.write( "18 + 4 = 3x
\n" ); document.write( "22 = 3x
\n" ); document.write( "x = \"22%2F3\"
\n" ); document.write( "x = 7\"1%2F3\" hrs, A working alone
\n" ); document.write( "then
\n" ); document.write( "3(7\"1%2F3\") = 22 hrs B working alone
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\n" ); document.write( "Check solution on Calc: 6/7.33 + 4/22 = 1.000; confirms our solution
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\n" ); document.write( "4.Peter can run around a 400m tract in 65 sec. How long does it take for John
\n" ); document.write( " to run the 400m if he meets Peter in 35 sec. After they start together in a
\n" ); document.write( " race around the tract in opposite direction? ?
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\n" ); document.write( "When they meet, they will have traveled a total of 400 meters in 35 seconds
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\n" ); document.write( "Find Peter's speed in meters/sec: \"400%2F65\" = 6.154 m/sec
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\n" ); document.write( "Let s = John's speed in m/sec
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\n" ); document.write( "Write a dist equation; Dist = time * speed
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\n" ); document.write( "35s + 35(6.154) = 400
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\n" ); document.write( "35s + 215.39 = 400
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\n" ); document.write( "35s = 400 - 215.39
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\n" ); document.write( "35s = 184.61
\n" ); document.write( "s = \"184.61%2F35\"
\n" ); document.write( "s = 5.275 m/sec is John's speed
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\n" ); document.write( "Find time for John to run 400 m:
\n" ); document.write( "\"400%2F5.275\" = 75.83 sec to run 400 m
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\n" ); document.write( "Check solution:
\n" ); document.write( "35 * 5.275 = 184.625 m
\n" ); document.write( "35 * 6.154 = 215.39
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\n" ); document.write( "Total dist = 400.0
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\n" ); document.write( "Do you have any questions about these?
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