Question

Subtract. simplify by collecting like radical term if possible
8sqrt20 -6sqrt5
I got 10sqrt5 is that right????????????

Answer 1

Yes

Answer 2

\[10\sqrt{5}\]

Answer 3

\[8\sqrt{20} - 6\sqrt{5}\]

Let's look at the square root of 20 first. 20 = 4*5 and since 4 is a perfect square we can write:

\[\sqrt{20} = \sqrt{4\cdot 5}=\sqrt{4}\cdot\sqrt{5}=2\sqrt{5}\]

So instead of writing \[\sqrt{20}\] write \[2\sqrt{5}\]

and now we have:

\[8\sqrt{20}=8\cdot (2\sqrt{5})=16\sqrt{5}\].

And
\[16\sqrt{5}-6\sqrt{5} =10\sqrt{5}\]

:)

Answer 4

Argh, I must learn to type faster. :-p

Answer 5

No your ok, thank you for your help