Write an equation for each line based on the given information.
* The line contains the point (1,3) and has a slope of 4.
* The line contains the point (4,0) and has a slope of -2/5.
* The line contains (0,-1) and (2,3).
Translate into system of eqations and solve:
* The sum of digits of a two-digit number is 12. If you reverse the digits, the new number is 36 greater than the original number. Find the original number.