Please help answer! It’s due today!

For number 5, we know that the triangles are not similar. Therefore, their corresponding sides are not proportional. I believe you could prove this by diving Triangle PQR’s side lengths with their corresponding side lengths in Triangle STU. I’ll do it below:
Side PQ corresponds to side TS. 9/7 is roughly 1.29, which would make that its scale factor. (I’m dividing because when side lengths are proportional, there is a specific value, the scale factor, that you can multiply or divide by to find the unknown side length of a corresponding side). Side QR corresponds to side UT. 15/10 is 1.5, thus making that the scale factor between these two sides. Finally, we see that side PR corresponds to side US. 12/8 is 1.5, making the scale factor between those two sides 1.5. Although two pairs of corresponding sides have the same scale factor, the same cannot be said for the third pair of corresponding sides. In order for the triangles to be similar, the scale factor should remain constant between each corresponding side, therefore, the triangles are not similar.
For number 6, since you are only given the side lengths, you would not be able to use the AA (Angle-Angle Similarity Theorem), or SAS (Side-Angle-Side Similarity Theorem). The calculations are shown below:
PQ~TS: 9/6= 1.5
QR~UT: 15/10= 1.5
PR~US: 12/8= 1.5

The scale factor for each pair of corresponding sides is congruent, proving that the triangles are proportional, making them similar.