### Video Transcript

The length of a rectangle is twice the sum of the width and 18. Write an equation for the length, π, in terms of the width, π€.

If the width of the rectangle is π€, then the sum of the width and 18 is π€ plus 18. We are told that the length is twice this sum. We need to multiply π€ plus 18 by two. The length π is therefore equal to two multiplied by π€ plus 18. We could distribute the parentheses or expand the brackets here. We could multiply two by π€ and two by 18. This means that π is also equal to two π€ plus 36. We could use either one of these equations to calculate the length when given the width or vice versa.