ATLAS Grade 8 The Number System. Practice it free.

$5 \times 5 \times 5 = 125\textsf{,}$ so $x = 5\textsf{.}$

$10 \times 10 \times 10 = 1{,}000\textsf{,}$ so $\sqrt[\text{\scriptsize 3}]{1{,}000} = 10\textsf{.}$

$\sqrt{5} \approx 2.236$.

$10 \times 10 \times 10 = 1{,}000\textsf{,}$ so $x = 10\textsf{.}$

$4 \times 4 \times 4 = 64$, so $\sqrt[3]{64} = 4$.

$6^{2} = 36$ and $7^{2} = 49\textsf{.}$ Since $36 < 40 < 49\textsf{,}$ $\sqrt{40}$ is between $6$ and $7\textsf{.}$

$9 \times 9 = 81$ and $(-9) \times (-9) = 81\textsf{,}$ so $x = \pm 9\textsf{.}$

$x = \sqrt{121} = 11$ because $11 \times 11 = 121$.