In the xy-plane, is the slope of line k positive?

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by Brent@GMATPrepNow » Fri Jan 22, 2010 12:10 pm
bhumika.k.shah wrote:(1) Line k passes through the points (-1, -7) and (2, 5).
(2) Line k has equation y = 4x minus 3.

OA D
(1) If we are given two points on a line, we can definitely find the slope (SUFFICIENT)
Slope = [(-7) - 5]/[(-1) - 2] = -12/-3 = 4

(2) If we are given the equation of a line, we can definitely find the slope (SUFFICIENT)
Here we are given the equation in slope, y-intercept form (y=mx+b, where m=slope and b=y-intercept)
So the line y=4x-3 has slope 4 (and y-intercept -3)

Answer: D
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