Express $156$ as a product of its prime factors.

The pair .......... is a like surds.

Show that the cube of any positive integer is of the form $4m, 4m+1$ or $4m+3$ for some integer $m$.

Determine whether the rational number $\frac{64}{455}$ has a terminating or non-terminating repeating decimal expansion. If it is terminating,write down its decimal expansion.

For any positive integer $n,$ prove that $n^{3}-n$ is divisible by $6.$

Every odd integer $a$ is in the form of $\ldots \ldots \ldots \ldots$ where,$k \in Z$.