SOLUTION: A number is of two digits one of which is square of other and the number is formed by reversing the digits exceeds twice the number by 15. find the number
Question 782696: A number is of two digits one of which is square of other and the number is formed by reversing the digits exceeds twice the number by 15. find the number Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A number is of two digits one of which is square of other and the number is formed by reversing the digits exceeds twice the number by 15. find the number
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Let the number be 10t+u
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u = t^2 -
10u+t = 2(10t+u)+15
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Substitute for "u" and solve for "t":
10t^2+t = 2(10t+t^2) + 15
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10t^2t +t = 20t + 2t^2 + 15
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8t^2 - 19t -15 = 0
Factor::
8t^2 -24t+5t -15
8t(t-3)+5(t-3)
(t-3)(8t+5) = 0
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Positive solution:
t = 3
u = t^2 = 9
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Number: 10t + u = 39
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