POSITIVE AND NEGATIVE SLOPES
Lines that go uphill from left to right have positive slopes. The steeper the uphill grade, the
greater the slope.Lines that go downhill from left to right have negative slopes. The steeper the downhill
grade, the less the slope.Lines parallel to the x-axis have slope = 0, and lines parallel to the y-axis have undefined slope.
Lines that are parallel to each other have the same slope, and lines that are perpendicular to each
other have negative-reciprocal slopes.