(5 x 10^4) - (1.25 x 10^2)

To solve the expression \((5 \times 10^4) - (1.25 \times 10^2)\), we first need to express both terms with the same exponent for the powers of 10, if possible.

1. Convert \(1.25 \times 10^2\) to have the same exponent as \(5 \times 10^4\):

\[
1.25 \times 10^2 = 1.25 \times 10^2 \times \frac{10^2}{10^2} = 1.25 \times 10^4 \times 10^{-2} = 0.0125 \times 10^4
\]

2. Now the expression becomes:

\[
(5 \times 10^4) - (0.0125 \times 10^4)
\]

3. Since both terms are now in the form of \(10^4\), we can combine them:

\[
(5 - 0.0125) \times 10^4 = 4.9875 \times 10^4
\]

4. The final result is:

\[
4.9875 \times 10^4
\]

So, the answer in scientific notation is:

\[
4.9875 \times 10^4
\]