## anonymous one year ago @dumbcow

1. anonymous

2. anonymous

do you know pythagorean thm ?

3. anonymous

Yea, for the most part.

4. anonymous

ok |dw:1440520824213:dw|

5. anonymous

So I tried subtracting 9^2 by 5^2 and got 56.. I'm not sure what I've done wrong...

6. anonymous

no thats right ... 81-25 = 56 now you have to take sqrt to solve for x $x^2 = 56$ $x = \sqrt{56}$

7. anonymous

I got 7.5 and it's not an option...

8. anonymous

right be careful, notice the answer choices leave as radical not decimal also we want Area, so we are not done $Area = 5*x = 5 \sqrt{56}$

9. anonymous

can you simplify the radical by factoring out a perfect square

10. anonymous

No. I have no clue what that even means o.o (I'm sorry I'm so horrible at this >.<)

11. anonymous

thats ok the goal is to get the number inside the radical(sqrt) as small as possible the only way to get rid of sprt is by having a perfect square .... 4,9,16,25... example: $\sqrt{9} = \sqrt{3^2} = 3$ also you can split up a sqrt into smaller factors example: $\sqrt{45} = \sqrt{9*5} = \sqrt{9} \sqrt{5} = 3 \sqrt{5}$ notice once you break it into sqrt9 and sqrt5 , you can get rid of sqrt9 because it equals 3

12. anonymous

so how do I do that with 56... I don't understand

13. anonymous

split it up ... like 45 has factors 9 and 5 what are factors of 56 .... try dividing by 4,9,16,25 etc

14. anonymous

1,2,4,7,8,14,28,56,

15. anonymous

yes look for perfect squares.... the only one is 4 4 pairs with 14 $\sqrt{56} = \sqrt{4*14} = \sqrt{4} \sqrt{14}$

16. anonymous

..so my answer would be 14?

17. anonymous

no dont try to jump ahead and just match a number to one of the answer choices we want AREA of rectangle with sides 5 and sqrt(56) we factored 56 into 4 and 14 $\sqrt{56} = \sqrt{4} \sqrt{14} = 2 \sqrt{14}$ Last multiply the 2 sides of rectangle to get AREA $Area = 5 * \sqrt{56} = 5 * 2 \sqrt{14} = 10 \sqrt{14}$

18. anonymous

Oh, okay. I think I get it now. Thanks.

19. anonymous

yw keep working on simplifying radicals

20. anonymous

gotta go :)

21. anonymous

Ok have a good day