If the distance between the points (x, -1) and (3, 2) is 5 units, find the positive value of x.

Using the distance formula, $\sqrt{(3 - x)^2 + (2 - (-1))^2} = 5$. Squaring both sides: $(3 - x)^2 + 3^2 = 25 \implies (3 - x)^2 + 9 = 25 \implies (3 - x)^2 = 16$. Taking square roots: $3 - x = \pm 4$. If $3 - x = 4$, then $x = -1$. If $3 - x = -4$, then $x = 7$. The positive value is $7$.