## anonymous 4 years ago need help with simplifying radicals

1. anonymous

|dw:1341559210514:dw|

2. asnaseer

the trick with these is to look at the number under the square root sign and see if you can express it as a product of a number that is a perfect square.

3. asnaseer

so think of how you can form 63 as a product of two numbers, one of which is a perfect square

4. anonymous

nope its not a perfect square

5. asnaseer

63 is not a perfect square, but can you express 63 as the product of two other numbers, one of which is a perfect square?

6. anonymous

can i do a factor tree?

7. asnaseer

yes

8. anonymous

ohk hold on

9. asnaseer

ok

10. anonymous

i got |dw:1341559648703:dw|

11. anonymous

thts wat i got? ignore the bottom part

12. asnaseer

not quite:$\sqrt{63}=\sqrt{9*7}=\sqrt{3^2*7}=3\sqrt{7}$

13. asnaseer

you have swapped the 3 and 7

14. anonymous

yea thts wat i meant

15. asnaseer

ok, now don't forget you also have to multiply by that 5 in the original question

16. anonymous

so 5 times the answer we got?

17. asnaseer

yes - thats right

18. asnaseer

19. anonymous

ohk hold on dnt leave yet

20. asnaseer

I won't - don't worry :)

21. anonymous

i got a decimal?

22. asnaseer

23. anonymous

ohhhhh

24. anonymous

|dw:1341559908464:dw|

25. asnaseer

perfect! well done!

26. anonymous

thnk u!!!!

27. asnaseer

yw :)