Question

3. A two-digit number is 3 more than 4 times the sum of its digits. If 18 is added to the number, it's digits are reversed. find the number ​

Answer 1

Answer:

The number is 35.

Step-by-step explanation:

let digit one = x

let digit 2 = y

Original number = 10x + y

given:

         10x + y = 4(x + y) + 3

   =    10x + y - 4x - 4y = 3

   =    6x - 3y - 3 = 0        -------(1)

 and  10x + y + 18 = 10y + x

   =     9x - 9y + 18 = 0     ------(2)

from eq(2) we can say that x = (-18 + 9y)/9 = y - 2     ------(3)

substituting the value of eq(3) in eq(1)

          6(y - 2) - 3y = 3

          6y - 12 - 3y = 3

          3y = 15

          y = 5      ------(4)

substituting eq(4) in eq(2)

          9x - 9(5) + 18 = 0

          9x = 27

          x = 3

Therefore x = 3 and y = 5.

Therefore the number is 10x + y = 35.