Step-by-step explanation:
m is the slope, b is the y-intercept (the y-value when x = 0).
m < 0 means the shore is negative, so, the line is going down, when viewing it from left to right. and it intercept the y-axis at a positive (b > 0) value.
so, the line (again, from left to right) goes first through the top left (II) quadrant. then it crosses at a positive y-value into the top right (I) quadrant. and from there then into the bottom right (IV) quadrant.
it therefore never passes through the bottom left (III) quadrant.
