Square roots

[Guest]

The correct simplification of -2 square root sign 48+7 square root sign 3 + 2 square root sign 146 is

choices given
13 square root sign 3
3 square root sign 48
5

How do you begin this one?

 

[Denis]

The correct simplification of -2 square root sign 48+7 square root sign 3 + 2 square root sign 146 is
choices given
13 square root sign 3
3 square root sign 48

Check that 146: should be 147, right?!!!

As example, sqrt(300) = sqrt(100*3) = 10sqrt(3)
Another example: sqrt(20) = sqrt(4*5) = 2sqrt(5)

Your expression is:
-2sqrt(48) + 7sqrt(3) + 2sqrt(147)
=-2(sqrt(16*3) + 7sqrt(3) + 2sqrt(49*3)

Take last term: 2sqrt(49*3) = 2*7sqrt(3) = 14sqrt(3)

Can you finish it?

 

[Guest]

Okay, I have been up since 5:30am working on this.

I think I GOT IT!!
Please, please, please tell me I am right.


-2sqrt(48) + 7sqrt(3) + 2sqrt(147)
=-2(sqrt(16*3) + 7sqrt(3) + 2sqrt(49*3)

Take last term: 2sqrt(49*3) = 2*7sqrt(3) = 14sqrt(3)
I did the same thing for the first term -2sqrt(48)=-2 sqrt (16*3)=-2sqrt (4*2 sqrt (3)=-8sqrt(3)

14 sqrt (3) + 7 sqrt (3) - 8sqrt (3)

Answer is 13 sqrt (3)

 

[Denis]

Bravo bethany! I'm proud of you :wink:

Now for practice, simplify: 7sqrt(72)

remember 1st step: find 2 appropriate numbers that multiply to 72.

 

[Guest]

Oh Denis, You are being mean to me!

Okay, here it goes.

7 sqrt 72
7 sqrt 9*8
7 sqrt 3*8
7*3=21
answer 21 sqrt 8

Am I close?

 

[Denis]

Oh Denis, You are being mean to me!
Okay, here it goes.
7 sqrt 72
7 sqrt 9*8
7 sqrt 3*8
7*3=21
answer 21 sqrt 8
Am I close?

VERY GOOD!
Can be simplified even more; always try for highest square possible;
in this case sqrt(36 * 2)

Now finish that one :evil:

 

[Guest]

Pushy, pushy I guess you are a beliver that practice makes perfect huh?

Okay,

7 sqrt 72
7 sqrt 36 *2
7 sqrt 6*2
7*6 is 42
answer is 42 sqrt 2

How did I do? I feel MUCH better about these thank you!!!!

 

[Denis]

Pushy, pushy I guess you are a beliver that practice makes perfect huh? Okay,
7 sqrt 72
7 sqrt 36 *2
7 sqrt 6*2
7*6 is 42
answer is 42 sqrt 2
How did I do? I feel MUCH better about these thank you!!!!

Yep; good job. Show like this: 42sqrt(2).

 

[Guest]

Thank you Denis. You are my light in a very dary tunnel.

 

[Denis]

Hmmm......
optimist: there is light at the end of the tunnel
pessimist: ya, ok, but that could be a train coming at me :roll: