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## #1 2017-11-14 10:13:39

emmakatecumbo
Member
Registered: 2017-09-22
Posts: 35

### Geometry homework

I am going to list my answers to my geometry homework. The ones I have already answered I need to take the sqrt if there are any perfect squares. The three i left blank I did not know how to answer. I will put the teachers comment down below. Help please I've been stuck for awhile and it needs to be done fast.
11. √108

12. √576

13. question : a=7 and c=SQRT 85

14. √24

15. question :  a=1 and c=SQRT 2

16. √44

17. √784

18. √306

19. question :  a=6 and c=6(SQRT 2)

20. √23

The ones you have completed look good... just make sure that if the numbers you get are PERFECT SQUARES... go ahead and take the SQRT.

For #13, 15 and 19... see my previous feedback!!!

previous feedback :

Make sure that you always STATE the final answer... if you end up wth c2 = 4... then c=2  which is the SQRT of 4.  Since 4 is a perfect square, you can give it's actual sqrt.  IF you were to get something like c2 = 5... your answer would just be c=√5.  Since 5 is NOT a perfect square, just leave the answer as a sqrt

Also... make sure that you understand when you SQUARE a SQRT... the operations CANCEL each other out and leave ONLY the number from under the radical!

Ex... √5 2 = √5 * √5 = 5

ex 2.... (2√5)2 = 2*2*√5*√5 = 4*5 = 20

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## #2 2017-11-14 21:59:38

bob bundy
Registered: 2010-06-20
Posts: 8,415

### Re: Geometry homework

Do you know how to 'reduce' a number to its prime factors?  I'll do

12. √576

as an example.

576 = 2 x 288 = 2 x 2 x 144 = 2 x 2 x 2 x 72 = 2 x 2 x 2 x 2 x 36 = 2 x 2 x 2 x 2 x 2 x 18 = 2 x 2 x 2 x 2 x 2 x 2 x 9 = 2 x 2 x 2 x 2 x 2 x 2 x 3 x 3

You keep dividing by prime factors until the resulting multiplication is all primes. http://www.mathsisfun.com/prime-factorization.html

Now you can see if the number is a perfect square:

2 x 2 x 2 x 2 x 2 x 2 x 3 x 3 = (2 x 2 x 2 x 3) x (2 x 2 x 2 x 3) = 24 x 24

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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