document.write( "Question 633416: If the unit's digit in the product (47x*729*345*343) is 5,what is the maximum number of values that x may take? \n" ); document.write( "
Algebra.Com's Answer #398872 by Edwin McCravy(20056)\"\" \"About 
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document.write( "(\"47x\"*729*345*343)\r\n" );
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document.write( "I assume you mean \"47x\" to be a three-digit number where\r\n" );
document.write( "4 is the hundreds digit, 7 is the tens digit and x is\r\n" );
document.write( "the units digit.  It cannot mean 47 times x, otherwise \r\n" );
document.write( "there would be infinitely many answers.\r\n" );
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document.write( "The result will have the same last digit as the last digit\r\n" );
document.write( "of the product of the last digits:\r\n" );
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document.write( "x*9*5*3 = 135*x\r\n" );
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document.write( "That will have the last digit the same as the last digit of\r\n" );
document.write( "5*x, and\r\n" );
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document.write( "5*1=5, 5*2=10, 5*3=15, 5*4=20, 5*5=25, 5*6=30, 5*7=35, 5*8=40, 5*9=45\r\n" );
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document.write( "So we see that if x is an even digit, the last digit will be 0, and\r\n" );
document.write( "if x is an odd digit, the last digit will be 5.\r\n" );
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document.write( "Therefore x must be an odd digit, either 1,3,5,7, or 9\r\n" );
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document.write( "Answer: The maximum number of digits x can be is 5.\r\n" );
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document.write( "Edwin
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