About how many miles
separate kinshasa,
democratic republic of the
congo, and kigali, rwanda?

Roughly 1,035.14 mi (1,665.90 km)

Explanation:

This is the straight-line measurement, measured along Google Earth. You can right-click and use the measuring tool form point to point. If you are given the map in the exam you can simply measure the distance using the scale that should be provided. To get an accurate reading measure the distance on a piece of paper and then put the piece of paper to the scale. The Democratic Republic of Congo borders Rwanda. However, there is a vast distance between both cities.

reflecting point a across the origin negates both of its coordinates.

b = (5, -4)