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## Comment on

Simplifying Rational Expressions## good

## If we plug in numbers to an

Quantity A: 3/2

Quantity B: 3/0

## Excellent question.

Excellent question.

I'm reluctant to provide a blanket response, since it's possible that I haven't considered every possibility.

That said, most of the time (perhaps even ALL of the time), when there's a variable in the denominator, the test-makers will include some kind of proviso that ensures that the denominator does not equal zero.

Rather than try to build an absolute rule around your idea, I think it's better to plug in more than 1 set of values.

ASIDE: If you had a question that looked like this...

QUANTITY A: 3/x

QUANTITY B: 3/y

...it's very likely that there would be a proviso that says something like x ≠ 0 and y ≠ 0 (or the more concise version: xy ≠ 0), However, even if there were no such proviso, we can quickly plug in two sets of values to show that the correct answer is D..

Cheers,

Brent

## Hi, I have a question

I had a problem solving the problem so I went straight to the explanation section,

It is hard to get the "step 2-3 " explanation.

How in step 2, the 2^29 + 2^29 later becomes in "step 3 " 2^30 ..

Please kindly explain. Thank you so much :)

## Hi Jenibae,

Hi Jenibae,

You'd like to know how/why 2^29 + 2^29 = 2^30

Good question.

Let's examine some similar examples:

x + x = 2x

k³ + k³ = 2k³

w² + w² = 2w²

7 + 7 = (2)(7)

135 + 135 = (2)(135)

Likewise, 2^29 + 2^29 = (2)(2^29)

= (2^1)(2^29)

= 2^30

Here's my step-by-step solution for that question: https://gre.myprepclub.com/forum/2-6286.html#p11148

Does that help?

Cheers,

Brent

## Hi,

If a question has a condition such as xy ≠ 0 or xy > 0, then still x & y both can be negative no.

Since (negative)(negative)= Positive.

Just need a confirmation

## That's correct. If we're told

That's correct. If we're told that xy ≠ 0 or xy > 0, then x and/or y can still be either positive or negative.

## For this question https:/

## Question link: https:/

Question link: https://gre.myprepclub.com/forum/36a-25b-ab-3588.html

To create equivalent fractions, we divide or multiply the numerator and denominator by the SAME value.

This is covered at 1:40 in the following video: https://www.greenlighttestprep.com/module/gre-arithmetic/video/1065

Cheers,

Brent