The straight line ax + by + c = 0, where abc≠0 will pass through the first quadrant if

If the line meets the x- and y-axes at A and B, thenA≡(−c/a,0),B≡(0,−c/b). The line will pass through the first quadrant if  −c/a>0 and / or −c/b>0 i.e., ac<0 and/or bc<0