Answer:
215 should be changed to 216 in order to make perfect cube.
Step-by-step explanation:
All should be a perfect cube, given
215x^18(y^3)(z^21)
215 cannot be write as cube of a number. Since it is not a perfect cube.
In order to make the perfect cube, we need to change 215 as 216.
6^3 = 6*6*6 = 216
All variables could make perfect cube.
x^18=(x^6)^3
y^3=y^3
z^21=(z^7)^3
The other terms are perfect cubes except for the first one. So 215 should be changed to 216 in order to make perfect cube.
Hope this will help to understand the concept.
Thank you.
