Question

Simplify : 5√45 + 3√20 - 4√5 pls solve

Answer 1

17
`√(5)`

Explanation:

using the rule of radicals

`√(ab)` ⇔
`√(a)` ×
`√(b)`

simplifying the given radicals

`√(45)`

=
`√(9(5))`

=
`√(9)` ×
`√(5)`

= 3
`√(5)`

-----------------

`√(20)`

=
`√(4(5))`

=
`√(4)` ×
`√(5)`

= 2
`√(5)`

------------------

Then

5
`√(45)` + 3
`√(20)` - 4
`√(5)`

= 5(3
`√(5)`) + 3(2
`√(5)`) - 4
`√(5)`

= 15
`√(5)` + 6
`√(5)` - 4
`√(5)` ← collect like radicals

= 21
`√(5)` - 4
`√(5)`

= 17
`√(5)`