Simplify: $1-[2-\{5-(4-3-2)\}]$

$617 + 6.017 + 0.617 + 6.0017 = ?$

If $a^{2}+b^{2}+c^{2}=ab+bc+ac,$ then the value of $\frac{a+c}{b}$ is:

If $x>1$ and $x^{2}+\frac{1}{x^{2}}=83,$ then $x^{3}-\frac{1}{x^{3}}$ is

If $\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right) \ldots\left(1-\frac{1}{70}\right)=\frac{x}{70},$ then what is the value of $x ?$

What is the value of $\frac{(0.5)^{3}-(0.1)^{3}}{(0.5)^{2}+0.5 \times 0.1+(0.1)^{2}}?$