Question

in which quadrant does the point (-10,-9) lie?

Answer 1

Quadrant 3 because it has negative coordinates only.
Hope this helps! :)

Answer 2

-- Negative x-coordinate (-10) sends you left from the origin.

-- Negative y-coordinate (-9) sends you down from the origin.

-- Left and down puts you in the lower left quadrant.  That's  Q-3 .