Question

If a 2 digit number, sum of the digits is 7. If the difference of 2 digit number and number obtained by reversing the digits is 9, then find the no.

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Answer 1

Answer:

let the digit at tens place be x and at unit place be y

sum of digit, x+y=7....(1)

original number=10x+y

number obtain by interchanging the digits=10y+x

difference,10x+y-10y-x=9

9x-9y=9

dividing by 9 on both sides

x-y=1....(2)

adding equation 1 and 2

x+y=7

-x-y=1

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2y=6

y=6/2

y=3

substituting y=3 in equation 2

x-3=1

x=1+3

x=4

the original number,10x+y=10×4+3

=40+3

=43

hope it helps you....

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Answer 2

16 because 7+9 =16

i hope it is right