## anonymous 5 years ago help with this equation PLEASE!?

1. anonymous

$y ^{5}-81y=0$

2. anonymous

First factor out a y

3. anonymous

I know there are 5 solutions, i'm just not sure exactly what the next steps look like.

4. anonymous

leaving y=0 y^4 - 81 =0

5. anonymous

y^4=81 y = +-81^1/4

6. anonymous

oh ok, so the other ones would be the same thing but 1/3, 1/3, 1...?

7. anonymous

i meant 1/2

8. anonymous

hmm fourth root of 81 is 3 3*3*3*3=81 solutions would be 0,3,-3

9. anonymous

it says it has 5 solutions

10. anonymous

the other 2 would be non-real solutions i believe

11. anonymous

if you graph this you will see it only crosses x-axis 3 times

12. anonymous

I don't need to graph it I just need to type in the 5 answers. What would the non real solutions be?

13. anonymous

ok y^2 +9 =0 y^2 = -9 y = sqrt(-9) = sqrt(9)*i y = +-3i

14. anonymous

so 0,-9,$\sqrt{9}\sqrt{9}$i, and -3i?

15. anonymous

sorry but my online assignment is picky with the format so i want to make sure I type it in correct

16. anonymous

oops, just realized i typed it wrong

17. anonymous

you are correct y = 0,-3,3,-3i,3i

18. anonymous

Oh, because it's the square root of that so this is the final answer.. Gotca, thanks!