document.write( "Question 1036895: I am a number between 70 and 80. The second digit is 3 smaller then the first digit. I know it's 74 because 7-4=3, but how can i solve it mathematically? \n" ); document.write( "

Algebra.Com's Answer #651589 by MathTherapy(10810) $\"\"$ $\"About$

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\n" ); document.write( "I am a number between 70 and 80. The second digit is 3 smaller then the first digit. I know it's 74 because 7-4=3, but how can i solve it mathematically?
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Let the tens and units digits be T and U, respectively
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document.write( "Then the number is: 10T + U 
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document.write( "Since it's between 70 and 80, T MUST be 7, and so the number is: 10(7) + U, or 70 + U
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document.write( "Also, it's given that the second (units) digit is 3 smaller than the first (tens) digit, so we can say that: U = T - 3, or U = 7 - 3, or 4
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document.write( "With the tens digit being 7 and the units digit, 4, the number's:  \n" );
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