Please help. Will go be brainliest

Ineed ! the person who answers and shows their work on they got the answer first will be marked the !

The sum of two numbers is 12 and their difference is 18 what are the two numbers

Solve this problem by using a 5d process or writing and solving an equation. no matter which method you use, be sure to define your variable and write an equation to represent the relationship a rectangle has a perimeter of 30 inches. its length is one less than three times its width what are the length and wodyh of the rectangle?