Let the two digits number = 10x +y where
tens place digit = x
units place digit = y
according to the first condition
x+y = 10................(1)
according to the second condition
10x + y + 18 = 10y + x
or, 10x- x + y -10y = -18
or, 9x - 9y = -18
x - y = -2..............(2)
solve the equestion 1 & 2 we get
x + y = 10
x - y = -2
´´´´´´´´´´´´´´´´´´´´´´´´
2x = 8
or, x = 4
put the value of x in equation (1) we get
4 + y = 10
or, y = 10 - 4
or, y = 6
so the two-digites number = 10x + y
= 10 × 4 + 6
= 46 Ans.
