Bananas1234 one year ago Simplify completely: square root of 81y^5

1. anonymous

59049

2. Bananas1234

i dont think that is what i need sorry.

3. Bananas1234

options: A. 9y^2 square root y B. 3y^2 C. 3y^2 square root 2y D. 9y square root y

4. Bananas1234

ok

5. Bananas1234

why?

6. Bananas1234

ok i think that makes sense

7. Bananas1234

ok thanks!

8. pooja195

Whats the square root of 81?

9. Bananas1234

9

10. pooja195

good $\huge~9*(y*y*y*y*y)$

11. anonymous

$\sqrt{81y^{5}} = \sqrt{81}*\sqrt{y^{4}}*\sqrt{y}$ You can think of it like this, which seems to be the approach of pooja above. Good luck :)

12. Bananas1234

9y

13. Bananas1234

9y square root y?

14. Bananas1234

@pooja195

15. pooja195

I agree with that. @Concentrationalizing is it right though? :/

16. anonymous

Well, given $\sqrt{81y^{5}} = \sqrt{81} * \sqrt{y^{4}} * \sqrt{y}$ $$\sqrt{81} = 9$$ For the $$\sqrt{y^{4}}$$ part, if we think of the square root as being an exponent of 1/2, we have: $\sqrt{y^{4}} = y^{4*\frac{1}{2}} = y^{2}$ The $$\sqrt{y}$$ part cannot be simplified. Put it all together and we have $$9y^{2}\sqrt{y}$$

17. Bananas1234

i think i understand that, Thank you!

18. anonymous

Of course :)