A number consist of 2 digits whose sum is 9 If 9is subtracted from the number the digits interchange - Maths - Linear Equations in One Variable

Question

A number consist of 2 digits whose sum is 9 If 9is subtracted
from the number the digits interchange their places Find the
number

Abhinav Verma · Answer

Let the digit at tens place be x
Units place be 9 - x
Original number = 10(x) + 9 - x = 9x + 9
New Number = 10(9 - x) + x = 90 - 10x + x = 90 - 9x
9x + 9 - 9 = 90 - 9x
9x = 90 - 9x
18x = 90
x = 5
Original Number = 10(5) + 9 - 5 = 50 + 4 = 54
ANs: The original number is 54

A number consist of 2 digits whose sum is 9. If 9is subtracted from the number the digits interchange their places. Find the number