To set up the distance formula correctly between the points \( L(4, 2) \) and \( M(7, 6) \), we use the formula:
\[ d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \]
Here \( L \) corresponds to \( (x_1, y_1) = (4, 2) \) and \( M \) corresponds to \( (x_2, y_2) = (7, 6) \). Therefore, we need to calculate:
\[ d = \sqrt{(7 - 4)^2 + (6 - 2)^2} \]
Thus, we would write:
\[ d = \sqrt{(4 - 7)^2 + (2 - 6)^2} \]
This matches the first option you provided:
\[ d = \sqrt{(4 - 7)^2 + (2 - 6)^2} \]
So, the correct setup of the distance formula is:
\[ d = \sqrt{(4 - 7)^2 + (2 - 6)^2} \]