Answers

2014-03-12T10:43:57+05:30
Let the A two digit number be (10x+y)

The product of its digits is 18 so,

x*y=18
x=18/y....................(1)

When 63 is subtracted from the number, The digits interchange their places, so

10x+y-63=10y+x

subsitute

10*18/y+y-63=10y+18/y

180/y+y-63=10y+18/y

multiply through by y to eliminate the fractions

180+y^2-63y=10y^2+18

collect terms

10y^+18=y^2-63y+180

9y^2 +63y -162 = 0

divide by 9

y^2+7y -18=0

Now just factor the equation and you will get the value of X and y thenyour untimate number will be (10x+Y).
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