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Question 236817: There is a two digit number that is 9 times the sum of its digits.
What is this number?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! There is a two digit number that is 9 times the sum of its digits.
What is this number?
:
A simple equation
10x + y = 9(x + y)
10x + y = 9x + 9y
10x - 9x = 9y - y
x = 8y
Obviously, y has to = 1, for x to equal a value less than 10
:
81 is the two digit number
:
Check:
81 = 9(1+8)
81 = 9(9)
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