Question

the sum of the digit of s 2digit no. is 7 .if digits are reversed ,the number formed 9less than the original no. find the no.
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Answer 1

Answer:

43

Step-by-step explanation:

numbers are x and y

number will become 10x + y

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Equation

x + y = 7

x = 7 - y ------------------------------ equation 1

(10x + y) - 9 = (10y + x)

10x + y - 9 = 10y + x

9x - 9y = 9

9 (x - y) = 9

x - y = 1

7 - y - y = 1 .................. (value taken from equation 1)

7 - 2y = 1

2y = 6

y = 3

x = 7 - y = 7 - 3 = 4

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number = 10x + y = 10*4 + 3 = 43