Thursday, May 10, 2018

What is a number whose cube is equal to the number itself but its square is not equal to the number itself

Answer:

It is always good if you solve first by your own.



x3=xx3=x

Subtract x2x2 from both sides to get:

x3−x2=−x2+xx3−x2=−x2+x

x(x2−x)=−1(x2−x)x(x2−x)=−1(x2−x)

Now, we know that x2x2 is not equal to xx, which means x2−xx2−x is not equal to zero. So, it’s safe to divide both sides by x2−xx2−x :

x=−1



So, the answer is -1.



Here, it was a key that since x and x square are not equal, x square - x can be cut from both sides of the equation. This results in x as minus 1 as the answer.