√20•√5-√63/√7

To simplify the expression √20•√5 - √63/√7, we can start by simplifying each square root individually, and then combine like terms.

First, let's simplify the square roots: √20 can be simplified as √(4•5). Taking the square root of 4 gives us 2. Therefore, √20 = 2√5.

Next, √63 can be simplified as √(9•7). Taking the square root of 9 gives us 3. Therefore, √63 = 3√7.

Now, let's combine the like terms: 2√5 - 3√7/√7

To combine the fractions with square roots, we need to have the same denominator (√7) for both terms. So let's rationalize the denominator:

(2√5 * √7)/√7 - 3√7/√7

Simplifying this further, we have: (2√35)/√7 - 3√7/√7

Now that both terms have the same denominator, we can combine the fractions: (2√35 - 3√7)/√7

And there you have it, the expression √20•√5 - √63/√7 simplifies to (2√35 - 3√7)/√7.