If the highest oxidation states shown by any Lanthanide and any Actinide are `+X and+Y`, the sum of `X+Y` is euqal to?

Answer

To solve the problem, we need to determine the highest oxidation states of both lanthanides and actinides and then find the sum of these oxidation states.

### Step-by-Step Solution:

1. **Identify the highest oxidation state of Lanthanides:**
- The lanthanides are the elements from Lanthanum (La) to Lutetium (Lu).
- The highest oxidation state that can be achieved by lanthanides is **+4**. This is typically seen in Cerium (Ce) and some other lanthanides.

2. **Identify the highest oxidation state of Actinides:**
- The actinides are the elements from Actinium (Ac) to Lawrencium (Lr).
- The highest oxidation state that can be achieved by actinides is **+7**. This is commonly seen in Uranium (U) and some other actinides.

3. **Assign values to X and Y:**
- From the above information, we can assign:
- \( X = 4 \) (for lanthanides)
- \( Y = 7 \) (for actinides)

4. **Calculate the sum of X and Y:**
- Now, we can find the sum:
\[ X + Y = 4 + 7 = 11 \]

5. **Conclusion:**
- The sum of the highest oxidation states of lanthanides and actinides is **11**.

### Final Answer:
The sum \( X + Y \) is equal to **11**.