Surds

[Ella]

I have the answers but I'm stuck on how you get them


1). 2√5 x 10 (answer = 10√2)
2). √10 x √20 (answer = 10√2)
3). 2√3 x 6 (answer = 6√2)
4). √88/ 2 (answer = √22)
5). And the questions circled on the photo

 

[Quaid]

I have the answers but I'm stuck on how you get them

1). 2√5 x 10 (answer = 10√2)
2). √10 x √20 (answer = 10√2)
3). 2√3 x 6 (answer = 6√2)
4). √88/ 2 (answer = √22)
5). And the questions circled on the photo

View attachment 3832

Hello Ella:

Where did you get the answers? The first answer is not correct. (I stopped reading, at that point.)

2√5 x 10 = 44.7214 (rounded)

10√2 = 14.1421 (rounded)


The forum guidelines request that we not post lists of exercises. To begin, let's work with one exercise. After we help you to understand it, you can retry the others on your own. If you get stuck again, post again.

Also, do you have any specific questions about what your lessons and examples have to say about simplifying square-root expressions like these? At what point are you stuck?

Cheers :cool:

 

[Deleted member 4993]

I have the answers but I'm stuck on how you get them

You must use grouping symbols to write the problems correctly

1) \(\displaystyle 2\sqrt{5 \cdot 10}\) must be written as 2√(5*10)

1). 2√5 x 10 (answer = 10√2)
2). √10 x √20 (answer = 10√2)
3). 2√3 x 6 (answer = 6√2)
4). √88/ 2 (answer = √22)
5). And the questions circled on the photo
View attachment 3832

Please correct your post using grouping symbols.

The general method to solve these problems is to write everything as prime factors.

1) (only 10 needs to be factorized) 2√(5*5*2) = 2*√(5²*2) = 2*5*√2 = 10√2

Now try rest of those.