posted by dee on .
can someone help me with simplification: ã20/5 - 1/ã5
my first answer is 1/ã5
my second answer is 10 -ã5/5
but the answere I have to choose from are:
(a) ã20 - 5ã5/ã5
(b) ã20 - ã5/5
(c) cannot be simplified
which is correct and if I'm not where did I go wrong?
√20/5 - 1/√5
= 2√5/5 - 1/√5*(√5/√5)
= 2√5/5 - √5/5
by the way:
1/√5 = √5/5 so your answer would be correct.
However, it is considered "better form" to have radicals in the denominator rationalized