SOLUTION: I am no good with square roots or cubic roots, could you please help me? a. The square root of x-1=3 b. The square root of 3 cubed=8 c. The cubic root of x squared =4.

Algebra ->  Square-cubic-other-roots -> SOLUTION: I am no good with square roots or cubic roots, could you please help me? a. The square root of x-1=3 b. The square root of 3 cubed=8 c. The cubic root of x squared =4.       Log On


   

Question 24595: I am no good with square roots or cubic roots, could you please help me?
a. The square root of x-1=3
b. The square root of 3 cubed=8
c. The cubic root of x squared =4.
For the third one I got x=12
here is my work for c:
cubic root of x squared=4 cubed
x squared=48
x=12
Can you tell me if I did this one right and let me know what I did wrong if not?
THANK YOU THANK YOU THANK YOU!!!!!
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
%28x%5E2%29%5E%281%2F3%29+=+4
cube both sides (raise each side to the 3 power
%28%28x%5E2%29%5E%281%2F3%29%29%5E3+=+4%5E3
take it slow - do every step
when you cube something, you multiply it by itself 3 times

the rule is you add the exponents when you have something like
2%5E2+%2A+2%5E2+%2A+2%5E2+=+2%5E%282+%2B+2+%2B+2%29+=+2%5E6+=+64
so you've got
%28x%5E2%29%5E%281%2F3+%2B+1%2F3+%2B+1%2F3%29+=+4%5E3
%28x%5E2%29%5E1+=+4%5E3
something raised to the 1 power is just the thing itself
take the square root of both sides
x+=+%284%5E3%29%5E%281%2F2%29
x+=+64%5E%281%2F2%29
x+=+8