205²-105²

To solve \( 205^2 - 105^2 \), we can use the difference of squares formula, which states that \( a^2 - b^2 = (a - b)(a + b) \).

Here, let:

• \( a = 205 \)
• \( b = 105 \)

Now, calculate:

\[ 205 - 105 = 100 \] \[ 205 + 105 = 310 \]

Now apply the difference of squares formula:

\[ 205^2 - 105^2 = (205 - 105)(205 + 105) = 100 \cdot 310 \]

Now multiply:

\[ 100 \cdot 310 = 31000 \]

So, \( 205^2 - 105^2 = 31000 \).