Question

Which number in the monomial 215x18y3z21 needs to be changed to make it a perfect cube?

Answer 1

215 needs to be changed to make it a perfect cube

Answer 2

Explanation:

The given monomial is
`215x^(18)y^(3)z^(21)`

We have tell the number in monomial to be changed to make it perfect cube.

We will convert each term of this monomial to perfect cube one by one.

(1)
`z^(21)=(z^(7+7+7))=(z^(7))(z^(7))(z^(7)) = (z^(7))^(3)`

(2) y³ = already given in perfect cube.

(3)
`x^(18)=(x^(6))(x^(6))(x^(6))=(x^(6))^(3)`

(4) 215 = 5 × 43 can not be converted into perfect cube.

So 215 needs to be changed.