Question

The sum of the digits of a two digit no is 9...if 45 is added to the no the digits are interchanged...find the no

Answer 1

Heya!
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▪Let the digit at ones place be 'x '

▪Let the digit at tens place be 'y'

♦Number formed => x + 10 y .....................(1)


➰According to the given question:
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x + y = 9

y = 9 - x .......................(2)


x + 10 y + 45 = 10x + y

-9x + 9y + 45 = 0


From (2)

-9x + 9 ( 9 - x ) + 45 = 0

-9x + 81 - 9x + 45 = 0

-18x + 126 = 0

-18x = -126

=> x = 7
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From (2)

y = 9 - 7

y = 2
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▪◾Number is x + 10y

=>> 7 + 10(2)

=>> 7 + 20

=> 27


♦Hence the Number is 27 ✔


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