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

(d) 1/5ã5

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

= √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