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# Tip 1: Eliminate common parts

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Tip 1: Eliminate common parts

This tip is for comparison questions in the GRE math section. The tip is to eliminate common parts. For example:

x>1

Left Side: x+3

Right Side: x2 + 2x – 3

If we factor the right side, we get (x+3)(x-1).

Next, see if there are any parts common to both sides. We see that (x+3) is on both sides. Divide both sides by (x+3), thus eliminating (x+3) from both sides. The left side becomes 1: (x+3)/(x+3) = 1, because a value divided by itself is 1.

Now we have 1 on the left side and (x-1) on the right side. We know that x>1. Let’s try to figure out what the smallest value for x-1 could be. If x is 1.1, (x-1) would equal 0.1. This is less than the left side, which is 1. Now let’s try to get the right side to be a number greater than the left side (which is 1). If x is 5, (x-1) equals 4. This is greater than the left side, which is still 1. So the answer to the comparison question will be (D) "The relationship cannot be determined from the information given," because neither side is greater or less all the time.

I hope this helped you! If it did, please take a moment to reply to this post. I would love to hear from you.