find the cube root

Question

³√-216/125

Answer 1

Cathryn,

 

Remember that a negative number cubed is negative, so the answer will be negative.

 

Notice that (5)³ = 125   and   (6)³ = 36(6) = 216  and finally that (-6/5)³ = (-6)³ / (5)³  = -216 / 125

 

So your answer is - 6/5.

Answer 2

The key to finding this answer lies in simplifying the problem and breaking it down to the correct components:

 

³√-216/125 = ³√(-216) / ³√(125) 

 

³√(-216) = -6, because -6*-6*-6 = 36 * -6 = -216

 

³√125 = 5, because 5*5*5 = 25*5 = 125

 

Thus,

 

³√-216/125 simplifies to -6/5 or -1 1/5 or -1.2