Simplifying Roots of Fractions

[medh2]

 

[lev888]

View attachment 19754

The two answers are the same.

 

[HallsofIvy]

\(\displaystyle a\frac{b}{c}= \frac{a}{1}\frac{b}{c}= \frac{ab}{c}\).

 

[medh2]

Hi Lev888

Thanks for replying.

Does it not matter that the 'a' is no longer in the numerator?

I tried to compare these on Mathway - which I pay for - but it said the second one wasn't an identity for the first.

 

[medh2]

\(\displaystyle a\frac{b}{c}= \frac{a}{1}\frac{b}{c}= \frac{ab}{c}\).

Thanks - can I also write ... ab(1/c)

 

[lev888]

Hi Lev888

Thanks for replying.

Does it not matter that the 'a' is no longer in the numerator?

I tried to compare these on Mathway - which I pay for - but it said the second one wasn't an identity for the first.

Can you post a screenshot?

 

[Steven G]

a is in the numerator in both cases.

 

[medh2]

Can you post a screenshot?

Strangely... I got two different results to the same equation... I have either typed something in incorrectly, or Mathway isn't as trustworthy as I thought.

 

[JeffM]

Seriously, you do not see that

[MATH]\sqrt{\dfrac{13^2 * 25}{4}} \equiv 13 * \dfrac{5}{2} \equiv \dfrac{13 * 5 }{2} \equiv \dfrac{65}{2}.[/MATH]
If you ever think that some statement about variables is mysterious, try substituting some numbers.

 

[lev888]

Strangely... I got two different results to the same equation... I have either typed something in incorrectly, or Mathway isn't as trustworthy as I thought.

Did you specify different domains? If a is negative, it's not an identity. Otherwise it is.

 

[topsquark]

Strangely... I got two different results to the same equation... I have either typed something in incorrectly, or Mathway isn't as trustworthy as I thought.

Looks like Mathway has a bug. I'd let them know. Maybe they can fix it.

-Dan

 

[Steven G]

For the record [math]\sqrt{x^2} \neq x[/math]. Just plug in say -7 for x and see if you get -7 back.