To find the distance between Alex's house at (-5, -4) and the library at (-5, -3), we can calculate the distance by looking at the vertical change since both points share the same x-coordinate.
The change in the y-coordinate is: \[ -3 - (-4) = -3 + 4 = 1 \]
Since each unit on the coordinate plane corresponds to 0.5 miles, the distance in miles is: \[ 1 , \text{unit} \times 0.5 , \text{miles/unit} = 0.5 , \text{miles} \]
Therefore, the distance from Alex's house to the library is 0.5 miles.