document.write( "Question 507472: it is a 4 digit number. the 2 digit is two times greater than the 3. the sum of all digits is three times than the last digit of the number. the product of the 3 and 4 digit is 12 times bigger than the ratio of the 2 to 3.? \n" ); document.write( "
Algebra.Com's Answer #340573 by ankor@dixie-net.com(22740)\"\" \"About 
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Write an equation for each statement, simplify and substitute if possible:
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\n" ); document.write( "It is a 4 digit number.
\n" ); document.write( "a, b, c, d; are the digits
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\n" ); document.write( "The 2nd digit is two times greater than the 3rd.
\n" ); document.write( "b = 2c
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\n" ); document.write( "the sum of all digits is three times than the last digit of the number.
\n" ); document.write( "a + b + c + d = 3d
\n" ); document.write( "a + b + c = 3d - d
\n" ); document.write( "a + b + c = 2d
\n" ); document.write( "substitute 2c for b
\n" ); document.write( "a + 2c + c = 2d
\n" ); document.write( "a + 3c = 2d
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\n" ); document.write( "the product of the 3 and 4 digit is 12 times bigger than the ratio of the 2nd to 3rd.?
\n" ); document.write( "c*d = 12(\"b%2Fc\")
\n" ); document.write( "Replace b with 2c
\n" ); document.write( "c*d = 12(\"%282c%29%2Fc\")
\n" ); document.write( "Cancel c and we have
\n" ); document.write( "c*d = 24
\n" ); document.write( "We have 4 unknowns and 3 equations, so we will have to make an logical guess
\n" ); document.write( "c=3, d=8; seems logical (d has to be the larger factor)
\n" ); document.write( "Go with that and using the 2nd equation we have:
\n" ); document.write( "a + 3c = 2d
\n" ); document.write( "a + 3(3) = 2(8)
\n" ); document.write( "a + 9 = 16
\n" ); document.write( "a = 16 - 9
\n" ); document.write( "a = 7
\n" ); document.write( "and
\n" ); document.write( "b = 2(3)
\n" ); document.write( "b = 6
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\n" ); document.write( "Our number: 7638
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\n" ); document.write( "Check this using a + b + c + d = 3d
\n" ); document.write( "7 + 6 + 3 + 8 = 3(8)
\n" ); document.write( "24 = 24
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