Answer:
1. k + 2 (or other way around, it doesn't matter)
2. PY or P×Y
3. 10 - z
Step-by-step explanation:
1. You are adding here, so you add the two terms together.
2. If we had the amount of rulers and how much they cost, we could multiply to find these. Since we don't, we just leave the two variables to be multiplied.
3. It is asking the difference between two numbers, meaning that you need to subtract. With these types of problems, you always use the first number that appears in the problem to start the expression. For instance, if it had listed z first, then you would have done z - 10.