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Question 494823: i found a two digit number less than 50 the sum of its digit was 12 their difference was 4 what number did i find
Answer by bucky(2189)   (Show Source):
You can put this solution on YOUR website! Let x equal one of the digits. And let y equal the other digit.
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You are told that the sum of the two digits is 12. So you can write an equation to express this as:
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x + y = 12
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Next you are told that the difference of the two digits is 4. In equation form this is:
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x - y = 4
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At this point you have a system of two independent equations that can be used to solve for the two unknowns.
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x + y = 12
x - y = 4
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If you add the two equations vertically, note that the +y and the -y will cancel each other and you are left with:
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2x = 16
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Solve for x by dividing both sides by 2 to get x = 8
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If one of the digits is 8 and the sum of the two digits is 12, then by subtraction you know that the other digit must be 4. So the two digits are 8 and 4.
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From your answers for the digits you know that the answer formed from the two digits of 8 and 4 must be either 48 or 84. But you were told that the two-digit number you are looking for is less than 50. So the answer to this problem must be 48.
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Hope this helps you.
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