The value of x equals the number of cubic units in a box that is 4 units high, 4 units deep, and 4 units wide.
Recall that the volume of a cube is given by
[tex]V=l\cdot w\cdot h[/tex]
Where l is the length, w is the width, and h is the height of the cube.
We are given that all three sides are 4 units.
So, the volume is
[tex]\begin{gathered} V=4\cdot4\cdot4\; \\ V=64\; \; cubic\; \text{units} \end{gathered}[/tex]
x must be equal to this volume
[tex]x=64[/tex]
Take cube root on both sides of the equation
[tex]\begin{gathered} \sqrt[3]{x}=\sqrt[3]{64} \\ \sqrt[3]{x}=\sqrt[3]{4^3} \\ \sqrt[3]{x}=4 \end{gathered}[/tex]
Therefore, the correct equation is the last option.
[tex]\sqrt[3]{x}=4[/tex]
