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# How does [(5/2)x^-2/(-2) simplify to (5/4)x^-2? watch

1. How does this:

Simplify to this:
Attachment 594968594970 Can you explain to me please? I don't get how it simplifies to that.
Thanks
Attached Images

2. The way I would have thought is that the 5/2, the 2 goes down to the bottom and is multiplied by the denominator, making the new denominator -4. (so it being -(5x^-2_)/-4
3. Multiply numerator and denominator by -2
4. (Original post by RogerOxon)
Multiply numerator and denominator by -2
How do you know to do that in order to get rid of the denominator? I thoought the rule in something like this was to bring the numerator of the fraction in the denominator over to the bottom and multiply that by the denominator.
5. First, consider that a/-b is identical to -(a/b). Therefore, our new expression is (5/2)(x^-2)/2. Try writing 5/2*x^-2 in fraction form, and see how you can apply fraction rules to simplify it.
6. (Original post by RogerOxon)
Multiply numerator and denominator by -2
When I multiply the numerator by -2, I get 10/2x^-2? What am I doing wrong?
7. (Original post by blobbybill)
When I multiply the numerator by -2, I get 10/2x^-2? What am I doing wrong?
That's right. You can divide 10 by 2.

Now you need to do the same to the denominator, so that you're not changing the value (ratio).
8. (Original post by blobbybill)
When I multiply the numerator by -2, I get 10/2x^-2? What am I doing wrong?
Assuming you mean 10*2x^-2, nothing. Continue evaluating it.
9. (Original post by _gcx)
Assuming you mean 10*2x^-2, nothing. Continue evaluating it.
No, they don't. That is the numerator multiplied by -2.

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