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## Comment on

Equation with Powers of 11## At around 00:30 in the video,

## Perfect! That works too.

Perfect! That works too.

## Do you have a few more

## Here are a few more:

Here are a few more:

- https://gmatclub.com/forum/if-0-0015-10-m-0-03-10-k-5-10-7-then-m-k-1450...

- https://gmatclub.com/forum/8-a-1-4-b-188024.html

- https://gmatclub.com/forum/if-5-13-9-7-3-15-x-what-is-the-value-of-x-219...

- https://gmatclub.com/forum/if-x-and-k-are-integers-and-12-x-4-2x-1-2-k-3...

Cheers,

Brent

## Hi,

There is something that seems very simple that I don't understand. I found -7/4 as a result because I did 12-8+4k = 4+4k. How do you find 4-4k?

Thanks,

## We want to simplify 12 - (8 +

We want to simplify 12 - (8 + 4k)

Here we're subtracting (8 + 4k) from 12, which means we must subtract 8 from 12 AND subtract 4k from 12.

So, 12 - (8 + 4k) = 12 - 8 - 4k = 4 - 4k

Here's another example;

Simplify 2x - (5 - 4x)

In this case, we're subtracting (5 - 4x) from 2x, which means we must subtract 5 from 2x AND subtract -4x from 2x

So, 2x - (5 - 4x) = 2x - 5 - (-4x) = 2x - 5 + 4x = 6x - 5

For more on this, check out my example at 4:42 in the following video: https://www.gmatprepnow.com/module/gmat-algebra-and-equation-solving/vid...

## I see the difference! Thank

## plug in value here is a

## Plugging in values will take

Plugging in values will take some time, but that strategy will definitely work!

## why -4k=-7 result in 4/7 but

## 4/7 and -4/-7 are equivalent

4/7 and -4/-7 are equivalent fractions.

Similarly, (-10) ÷ (-2) = 5 and 10 ÷ 2 = 5

Here, we're applying the rule that says (negative) ÷ (negative) = positive

## So it is implied that -7/-4

## Yes, the fraction -7/-4 is

Yes, the fraction -7/-4 is positive.

We can use equivalent fractions to show why: -7/-4 = (-1)(7)/(-1)(4) = (-1/-1)(7/4) = (1)(7/4) = 7/4