After interchanging the given two signs, what will be the value of the following expression?

× And ÷

20 + 5 ÷ 6 × 2 – 5

? – 2³ =(7² – 12 ) + ( 10² -17)

If x = 222, y = 223 and z = 224, then find the value of x³+y³+z³-3xyz

If the sum of {a\over b}and its reciprocal is 1 and a ≠ 0, b ≠ 0, then the value of a³ + b³ is

If $${b\over a}=0.7$$ find the value of $${a-b\over a+b}={11\over34}.$$

What should come in place of the question mark (?) in the following mathematical statement?
$${{?^6÷16=108}}$$

$$ if \ {1\over x}+x=4,$$ then find $${1\over x^2}+x^2$$

The value of $$5-{8+2\sqrt{15} \over4}-{{1}\over8+2\sqrt{15}}$$ is equal to: