• April 23rd 2008, 05:11 PM
Power
6 / (3 + √5) = (18 - 6√5) / 4

my question is that can u subtract 6 from 18..why or why not?
• April 23rd 2008, 05:17 PM
Mathstud28
Quote:

Originally Posted by Power
6 / (3 + √5) = (18 - 6√5) / 4

my question is that can u subtract 6 from 18..why or why not?

$\frac{6}{3+\sqrt{5}}=\frac{18-6\sqrt{5}}{4}$

Multiplying both sides gets you $\frac{24}{3+\sqrt{5}}=18-6\sqrt{5}$

now if you are asking from here can you subtract the asnwer is no because the two numbers do not have a common denominator
• April 23rd 2008, 05:18 PM
Morgan82
Quote:

Originally Posted by Power
6 / (3 + √5) = (18 - 6√5) / 4

my question is that can u subtract 6 from 18..why or why not?

No. This is kind of how I saw it...
the radical is like a variable...
and the 18 and 6 are not like terms..
...just a thought...
But I know you cant (Nod)