SOLUTION: Ok, these type of problems scare me to no end. Can someone please help me with a step by step explanation. Thanks 1. sqrt w-9=8 2. not sure how to write this problem but it h

Algebra ->  Square-cubic-other-roots -> SOLUTION: Ok, these type of problems scare me to no end. Can someone please help me with a step by step explanation. Thanks 1. sqrt w-9=8 2. not sure how to write this problem but it h      Log On


   

Question 231256: Ok, these type of problems scare me to no end. Can someone please help me with a step by step explanation. Thanks
1. sqrt w-9=8
2. not sure how to write this problem but it has a 3, then the sqrt sign and inside the sqrt sign is -64.
3. this one is similar where it has 3 sqrt sign and 16 inside the sqrt.
Any help with either problem is greatly appreciated.
Found 2 solutions by josmiceli, texttutoring:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
I'll take a stab at them
sqrt%28w-9%29+=+8
sqare both sides
w-9+=+64
Add 9 to both sides
w+=+73
--------------
This one looks like a cube root. When the
cube root is asked for, they are saying:
"What number multiplied by itself 3 times
will give the number under the cube root sign?
cube root(-64) = -4 because
%28-4%29%2A%28-4%29%2A%28-4%29+=+-64
---------------------------------
cube root(16) = cube root(8%2A2)
cube root(16) = cube root(8) x cube root(2)
cube root(16) = 2 x cube root(2)
This is because 8+=+2%2A2%2A2

Answer by texttutoring(324) About Me  (Show Source):
You can put this solution on YOUR website!

1. sqrt%28w-9%29=8
Square both sides to remove the square root sign.
(w-9)=64
w=73

2. What you are describing is the 3rd root of -64. Ask yourself, what number when multiplied by itself 3 times, equals -64?
The answer is -4 because (-4)*(-4)*(-4)=-64
Your calculator should have a 3rd root button.
3. Are you sure it wasn't a 4 sqrt sign and 16 inside the sqrt?
I ask because 16 does not have 3rd root that is a rational number.
However, the 4th root of 16 is 2, because 2*2*2*2=16