We're trying to find out if a line cuts through the first quadrant (top right).
ALL lines with a positive slope will cross through the first quadrant
SOME lines with a negative slope will cross through the first quadrant I. the line has x-intercept=-1
Tells us that the line crosses the x axis at (-1,0). Whether it passes through the first quadrant depends on it's slope, which we don't have, so this statement is insufficient.
INSUFFICIENTII. the slope of the line is greater than 1
Tells us that the line has a positive slope, so it WILL pass through the first quadrant.
A vertical line has an undefined slope because slope = rise/run and a vertical line has a run of 0 (and you can't divide by 0) so the slope is undefined. A horizontal line has a slope of 0. The fact that statement 2 says it has a slope greater than 1 tells us it's not a vertical or horizontal line, and that it does cross the first quadrant at some point.