Question

6. The sum of the digits of a 2-digit number is 9. If the digits of the number are reversed, the new numbe
is decreased by 9. Find the number.
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Answer 1

Answer:

54

Step-by-step explanation:

x + y = 9

10x +y -9 =10y +x

10x -x -9 =10y -y

9x -9 =9y

9x-9y=9

9(x-y)=9

x-y=1

x+y+x-y=10

2x=10

x = 5

y = 4

original number = 54

Answer 2

Answer:

let the two digit number be ab. then 10a+b=9 and the digits are reversed i.e ba the number decreased by 9 so 10b+a-9=10a+b that implies b= a+1 substitute in any of above equation you will get answer hope you have understand this