Question

Difference of two perfect cubes is 387. If the cube root of the greater of two numbers is 8,find the cube root of the smaller number.

Answer 1

Let greater no be x and smaller be y.

By question, x^3-y^3=387......(1)

Also, x^3=8........(2)

Now, from (2),. x^3=(2)^3

Therefore, x =2.

Using this value of x in (1), we get

8-y^3=387

Or,y^3=-379

Therefore y= -7.236

Answer 2

$\bf\tt{ANSWER}$

Let the greater number be x

Let the smaller number be y.

Given:

The cube root of the greater of two numbers is 8.

We have assumed x = greater number, so,

³√x = 8

Now to simply the root, we will cube both the sides.

(³√x)³= 8³

x = 512.

Now, given that;

Difference of two perfect cubes is 387.

x - y = 387

512 - y = 387

512 - 387 = y

125 = y

³√125 = y

5 = y

•°• the cube root of the smaller number = y = 5