Hey, CadenClough! For this, it's best to use algebra. We know that rectangles have two of each measure: two lengths and two widths. This means the formula to find the complete perimeter of the rectangle is 2l + 2w = p.
Now let's look at the problem. For length, we have x + 3 and for width we have 2x - 6. First off, fill in the values for length and width in the perimeter equation like this:
Question order asks ratio from outside time to inside time so the 40 would come first. also, all the above are correct. You can write a ratio as a fraction, with a colon, or with the word to.