Question

product of the digits of a two no. is 18 . when we interchange the digits it is found that the resulting new number is smaller then the original number by 63 what is the two digit no.
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Answer 1

Answer:

92

Step-by-step explanation:

let the two digit number be 10x+ y

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

10x + y - 63 = 10 y + x

9x - 9y - 63= 0

9x - 9y = 63

x-y = 7..........(.2)

x= 7+y

put value of x in eq 1b, we get

( 7+y ). y = 18

y² + 7y = 18

y² +7y-18=0

y² +9y -2y -18= 0

y(y+9) -2 ( y +9) =0

( y+9) (y-2). = 0

y=-9 , y = 2

y= 2........

so, x= 7+2=9

therefore the two digit number is 10(9)+2

= 92

HOPE IT HELPS YOU