 This video is called Solving Problems Using Proportional Parts, Part 2. In this particular figure, we have these parallel line symbols, and so that means that these side lengths are broken up into proportional parts. And so to set up our ratios, we would use x plus 3 and x minus 2, 7, and, uh oh, we seem to be missing a side. Since the entire length is 12 and part of it is 7, I know the remaining piece has to be 5 units long. So now we can set up our ratio. And then let's cross multiply to solve. 5 times the quantity x plus 3 is equal to 7 times the quantity x minus 2. Let's use the distributive property. And now we can subtract 5x from both sides. Add 14 to both sides. And so we get that x is equal to 29 halves. This next problem deals with the second theorem on the front page of your note sheet. So we have x and x plus 5 are split up. And 5 and 14 create the final proportions. Let's cross multiply. 14x is equal to 5 times x plus 5. Distribute. And then solving gives us that x is equal to 25 ninths.