Let's solve each problem step-by-step.

### Bài 1
#### a) \((45 - 5 \times 9) \times 2 \times 3 \times 4 \times 5 \times 6 \times 7 \times 8 \times 9\)
1. Calculate the expression inside the parentheses:
\[
45 - 5 \times 9 = 45 - 45 = 0
\]
2. Multiply the result by the rest of the terms:
\[
0 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7 \times 8 \times 9 = 0
\]

The result of a) is \(0\).


#### b) \((23 + 24 + 25 + \ldots + 56 + 57) \times (7 \times 8 - 56)\)
1. Calculate the sum inside the parentheses:
- This is an arithmetic series. The sum \(S\) of an arithmetic series can be found by the formula:
\[
S = \frac{n}{2} \times (a + l)
\]
Where \(n\) is the number of terms, \(a\) is the first term, and \(l\) is the last term.
- Here, \(a = 23\) and \(l = 57\).
- The number of terms \(n\) is calculated as:
\[
n = (l - a + 1) = (57 - 23 + 1) = 35
\]
- Now, calculate \(S\):
\[
S = \frac{35}{2} \times (23 + 57) = \frac{35}{2} \times 80 = 35 \times 40 = 1400
\]
2. Calculate the value of the second parentheses:
\[
7 \times 8 - 56 = 56 - 56 = 0
\]
3. Multiply the results:
\[
1400 \times 0 = 0
\]

The result of b) is \(0\).


#### c) \((m \times 1 - m : 1) \times 23 \times 24 \times 234 \times 343\)
1. Simplify the expression inside the parentheses:
\[
m \times 1 - \frac{m}{1} = m - m = 0
\]
2. Multiply the result by the rest of the terms:
\[
0 \times 23 \times 24 \times 234 \times 343 = 0
\]

The result of c) is \(0\).


#### d) \(2 \times 4 \times 16 \times 25 \times 50 \times 125\)
1. Compute the product:
- Let's first simplify some of the terms for easier computation:
\[
2 = 2, \; 4 = 2^2, \; 16 = 2^4, \; 25 = 5^2, \; 50 = 2 \times 5^2, \; 125 = 5^3
\]
- Combine the factors of 2 and 5:
\[
2 \times 2^2 \times 2^4 \times 2 \times 5^2 \times 5^2 \times 5^3
\]
- Gather the exponents:
\[
2^{1+2+4+1} \times 5^{2+2+3} = 2^8 \times 5^7 = 256 \times 78125
\]
2. Multiply the results:
\[
256 \times 78125 = 20000000
\]

The result of d) is \(20,000,000\).