Answer:
See below.
Step-by-step explanation:
Multiply out the numbers on each line to the right and see which line on hte left they correspond to.
1. 2rs = 2 * r * s
2. 18rst = 2 * 3 * 3 * r * s * t
3. 25ab = 5 * 5 * a * b
4. 30abc = 2 * 3 * 5 * a * b * c
5. 45abr = 3 * 3 * 5 * a * b * r
