Simplify the expression 2√20 - 3√7 - 2√5 + 4√63.

Solution:

The given expression is

2√20 - 3√7 - 2√5 + 4√63

By simplifying the surds

2√20 = 2√(5 × 4) = 4√5  

4√63 = 4√(9 × 7) = 12√7

Now substituting the simplified version

2√20 - 3√7 - 2√5 + 4√63 = 4√5 - 3√7 - 2√5 + 12√7

By further simplification

= 4√5 - 2√5 + 12√7 - 3√7

= 2√5 + 9√7

Therefore, by simplifying the expression we get 2√5 + 9√7.

Simplify the expression 2√20 - 3√7 - 2√5 + 4√63.

Summary:

Simplifying  the expression 2√20 - 3√7 - 2√5 + 4√63 we get 2√5 + 9√7.