Question

25) The sum of the digits of a 2-digit number is 7. Then the number obtained
by reversing the digits is 2 more than twice the original number. Find the
number.​

Answer 1

Step-by-step explanation:

Let the unit place digit be x

and tens place digit be (7-x) [as sum of digits is 7]

original number = 10× tens place digit + 1×unit place digit

= 10×(7-x) + 1×x

= 70-10x + x

= 70-9x

Now,

Number obtained by reversing the digits will be,

reversed number = 10× unit place digit + 1 × tens place digit

= 10×x + 1× (7-x)

=10x + 7-x

=9x+7

A.T.Q.

reversed number = 2 + 2×original number

9x+7 = 2 + 2(70-9x)

9x+7 = 2 + 140-18x

18x + 9x = 2 + 140-7

27x = 135

x = 135÷27

x = 5

original number = 70-9x

= 70-9×5

= 70-45

= 25

Thank You!!!!!