A triangle is formed by the x-axis, the y-axis, and Line M.

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A triangle is formed by the x-axis, the y-axis, and Line M. Is the area of this triangle greater than 5?

(1) Line M has a slope of −4/3.

(2) The x-intercept of Line M is 25% less than the y-intercept.

[spoiler]OA=E[/spoiler]

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by Ian Stewart » Mon Jul 01, 2019 6:04 am

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Gmat_mission wrote: (2) The x-intercept of Line M is 25% less than the y-intercept.
There's a reason you never see percentages combined with coordinate geometry in any actual GMAT question: intercepts and slopes can be negative, and the GMAT will never ask you to work out what number is "25% less than" some negative number. It's also not even clear what Statement 2 is talking about: "The x-intercept of Line M is 25% less than the y-intercept." Which y-intercept? There are three lines in the question, not one.

So the question is very carelessly written, but if we reinterpret Statement 2 to say "the x-intercept of M is 3/4 of the y-intercept of M", then the two Statements say the same thing. Visually, we only know the slope of the line -- if it hits the y-axis only millimeters above the origin, the area of the triangle will be minuscule, and if it hits the y-axis at y = 1,000,000, the triangle will be enormous. Or you can notice that when you let y = 0 in the equation of a line y=mx+b and solve for x, you find x = -b/m = (-1/m)b, so if m = -4/3, it will automatically be true that the x-intercept = (3/4)b, so is automatically 3/4 of the y-intercept, and Statement 1 and 2 give identical information, and since Statement 1 is not sufficient, the answer must be E.
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