Let's solve the equations step by step.

### Equation C:
**x - (45 + 56) = 21**

1. First, simplify the expression inside the parentheses:
- \( 45 + 56 = 101 \)

2. Substitute back into the equation:
- \( x - 101 = 21 \)

3. To isolate \( x \), add 101 to both sides:
- \( x = 21 + 101 \)
- \( x = 122 \)

### Equation 1:
**173 - (2) = 212**

1. This equation states that 173 minus 2 equals 212:
- \( 173 - 2 = 171 \)

2. Clearly, \( 171 \) does not equal \( 212 \), so this equation is incorrect.

### Summary:
- For Equation C, the value of \( x \) is **122**.
- Equation 1 is **not valid** as \( 173 - 2 \) equals \( 171 \), not \( 212 \).

If you need further assistance or have more questions, feel free to ask!

x-(45+56)=21
x-101=21
x=122