Question

Simplify 4√20- 3√45. Show your work.
Answer:

Answer 1

-
`√(5)`

Explanation:

using the rule of radicals

`√(a)` ×
`√(b)` ⇔
`√(ab)`

simplifying radicals

`√(20)`

=
`√(4(5))`

=
`√(4)` ×
`√(5)`

= 2
`√(5)`

and

`√(45)`

=
`√(9(5))`

=
`√(9)` ×
`√(5)`

= 3
`√(5)`

Then

4
`√(20)` - 3
`√(45)`

= 4(2
`√(5)` ) - 3(3
`√(5)` )

= 8
`√(5)` - 9
`√(5)`

= -
`√(5)`