Question

How do you simplify `sqrt5-4sqrt20`?

Answer 1

`-7sqrt5`

Explanation:

`"using the "color(blue)"law of radicals"`

`•color(white)(x)sqrtaxxsqrtbhArrsqrt(ab)`

`rArrsqrt5-4(sqrt(4xx5))`

`=sqrt5-4(sqrt4xxsqrt5)`

`=sqrt5-4(2sqrt5)`

`=sqrt5-8sqrt5larrcolor(blue)" collect like radicals"`

`=-7sqrt5`