Simplify the radicals and collect the like terms
√45 - √20
To simplify the radicals and collect like terms, first simplify the individual radicals:
√45 can be simplified as √(9*5) = √9 * √5 = 3√5
√20 can be simplified as √(4*5) = √4 * √5 = 2√5
Now, substitute these simplified radical expressions back into the original equation:
√45 - √20 = 3√5 - 2√5 = (3 - 2)√5 = √5