You can. but it is preferred if you do not. This is because it is generally easier to estimate the value with a radical in the numerator than in the denominator.
For example, given that sqrt(2) = 1.414, approx estimating the value of 3/sqrt(2) is not easy since it requires division by 2.414 However, 3/sqrt(2) = 3*sqrt(2)/2 = 3*1.414/2 = 3*0.707 = 2.121 - a calculation that any half-way competent pupil an carry out in their head.
It is called rationalising the denominator.
"rationalizing" the denominator
It could be written as 28 divided by radical 3. However, you will normally be required to rationalise the denominator which brings you back to 28 radical 3 divided by 3.
The 6th radical is raising something to the 1/6 power, and the 5th radical is the 1/5 power. Dividing means you subtract the exponents, and 1/6-1/5 is -1/30. The answer would be 1/(30th rad of the term).
Simplest radical form means simplifying a radical so that there are no more square roots, cube roots, 4th roots and such left to find. It also means removing any radicals in the denominator of a fraction.
To eliminate the radical in the denominator.
when there is no radical in the denominator
Rationalise the denominator.
Rationalising the denominator.
No. One of the rules for "simplest form" is that there may be no radical in the denominator. To fix this, multiply top and bottom of the fraction by the radical denominator. For example, ( 1 / √2) = (1 / √2)(√2 / √2) = (√2 / 2)
It is called rationalisation [of the denominator].
It is called rationalising the denominator.
"rationalizing" the denominator
It is called rationalising the denominator.
It isn't clear what, exactly, you want to achieve. To write a fraction in standard form, it is customary to leave no radical in the denominator; in this case, for example, if you have square root of 2 in the denominator, you would multiply top and bottom by square root of 2, precisely to get rid of the radical in the denominator.
does it stay a fraction
No, you can also use conjugates with more than one radical term. For example, if the denominator is root(2) + root(3), you can use the conjugate root(2) - root(3) to rationalize the denominator.