did I simplify these sqaure roots right???

[Guest]

1. sqrt 7 8 sqrt 18/sqrt 2= I got 3sqrt 7

2. sqrt 10 8 sqrt16/sqrt5 = I got 4sqrt2

And the last one38sqrt 8/64= I got 3sqrt3/4

 

[Denis]

Please repost CLEARLY!

Like: And the last one38sqrt 8/64

Is that 38sqrt(8) / 64 or 38sqrt(8/64) ?

 

[Guest]

sorry hope this is better

1. the square root of 7 times the square root of 18 over the square root of 2=
I got 3 times the square root of 7.

2. the square root of 10 times the square root of 16 all over (divided by the square root of 5=
I got 4 times the square root of 2.

3. I have this problem posted twice so will fix this one and cancle the other one.
3 times the square root of 8 over 64...the book has the answer as 3 times the square root of 2 all divided by 4 but I get 3 times the aquare root of 8 all over 8?

 

[Denis]

Re: sorry hope this is better

1. the square root of 7 times the square root of 18 over the square root of 2 = ?
I got 3 times the square root of 7.

Correct!
sqrt(18)sqrt(7) / sqrt(2)
= sqrt(9)sqrt(2)sqrt(7) / sqrt(2)
= sqrt(9)sqrt(7)
= 3sqrt(7)

2. the square root of 10 times the square root of 16 all over (divided by the square root of 5 = ?
I got 4 times the square root of 2.

Correct again!
sqrt(16)sqrt(10) / sqrt(5)
= 4sqrt(5)sqrt(2) / sqrt(5)
= 4sqrt(2)

3. 3 times the square root of 8 over 64...the book has the answer as 3 times the square root of 2 all divided by 4 but I get 3 times the aquare root of 8 all over 8?

Incorrect; how did you arrive at that?

3sqrt(8/64)
= 3sqrt(1/8)
= 3sqrt(1) / sqrt(8)
= 3 / sqrt(4)sqrt(2)
= 3 / 2sqrt(2)

Looks like your "book" went at it this way:
3sqrt(8/64)
= 3sqrt(8) / sqrt(64)
= 3sqrt(4)sqrt(2) / 8
= 3(2)sqrt(2) / 8
= 3sqrt(2) / 4

Both are correct; I don't know which is the most "proper";
perhaps someone else will enlighten us :?:

So I was previously wrong: you can't ask for a refund :shock:

 

[Guest]

Thanks !

I will ahve my son asked about the last one and see which answer she uses and why!