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ddm
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PostPosted: Thu Aug 28, 2008 5:10 pm    Post subject: units digit Reply with quote
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Sunny22uk
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PostPosted: Thu Aug 28, 2008 5:49 pm    Post subject: Reply with quote
since X3 x 3 = 2y x 9
it follow that x3=2y x 3 ( divide both sides by 3)
since x and y are between 1 and 10, it folllows that y=1(units digit has to be equal on the right hand side and left hand side)
Right hand side= 63
x=6,y=1, answer=7
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ddm
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PostPosted: Fri Aug 29, 2008 2:37 pm    Post subject: Reply with quote
"it folllows that y=1(units digit has to be equal on the right hand side and left hand side)"???

How did u get that?
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Sunny22uk
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PostPosted: Fri Aug 29, 2008 2:50 pm    Post subject: Reply with quote
Sunny22uk wrote:
since X3 x 3 = 2y x 9
it follow that x3=2y x 3 ( divide both sides by 3)
since x and y are between 1 and 10, it folllows that y=1(units digit has to be equal on the right hand side and left hand side)
Right hand side= 63
x=6,y=1, answer=7


>>the units digit on the left hand side is 3
>>the units digit on the right hand side must be 3(for the two numbers to be equal)
>>Units digit of 2yx3 means yx3
>>for yx3 to be equal to 3 and y being between 1 and 10, y=1 is the only value which will give the desire result

Let me know if you have any questions
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