A rectangle has a length 6 more than its width. If the width is decreased by 2 and the length decreased by 4, the resulting rectangle has an area of 21 square units. What is the length of the original rectangle? What is the ratio of the original rectangle's area to the new rectangle's area? what is the perimeter of the new rectangle? Show all your work.

Can someone please show me how you did this? I'm lost.