Answer:
47
Explanation:
We can take x to represent the 10s digit and y the ones digit. Then we have ...
(10x +y) - 4(x+y) = 3. . . . . a number exceeds 4 times the digit sum by 3
(10x +y) +27 = (10y +x) . . . . . adding 27 swaps the digits
Simplifying these equations to standard form gives ...
2x - y = 1
x - y = -3
Subtracting the second equation from the first gives ...
x = 4
y = 2x -1 = 7
The number is 47.