Question

A two digit number is such that sum of its digits is 4. 1f 18 is added to the number its digits are
reversed. Find the number.​

Answer 1

Answer:

Step-by-step explanation:

let the two digit no. be 10x+y

x+y=4

10x+y+18=10y+x

9x-9y+18=0

x-y=-2

x=1, y=3

number is 13

Answer 2

let the one place number is x and tenth place number is y
so number is 10y + x
It's given that x + y = 4
x= 4 - y
According to the question

(10y+x)+18=10x+y
10y + 4 - y +18 = 10 (4 - y) + y
9y+22= 40-10y+y
9y +9y = 40 -22
18 y = 18
y = 1
so x = 4 - y
x = 4 - 1
x = 3
and number is 10y +x = 10 + 3 = 13