Question:
The positive solutions of the equation ax + by + c = 0 always lie in the
(a) Ist quadrant
(b) IInd quadrant
(c) IIIrd quadrant
(d) IVth quadrant
Solution:
(a) We know that, if a line passes through the Ist quadrant, then all solution lying on the line in first quadrant must be positive because the coordinate
of all points in the Ist quadrant are positive.