If $\sqrt{9x^2+6x+1} < (2-x)$,then:

$A$ solution is to be kept between $30^{\circ} C$ and $35^{\circ} C$. What is the range of temperature in degree Fahrenheit,if the conversion formula is $F = \frac{9}{5} C + 32$?

$A$ manufacturer has $600 \text{ litres}$ of a $12 \%$ solution of acid. How many litres of a $30 \%$ acid solution must be added to it so that the acid content in the resulting mixture will be more than $15 \%$ but less than $18 \%$?

The water acidity in a pool is considered normal when the average pH reading of three daily measurements is between $8.2$ and $8.5$. If the first two pH readings are $8.48$ and $8.35$,then find the range of $pH$ value for the third reading that will result in the acidity level being normal.

Solve the following inequality: $\frac{|x+2|-x}{x} < 2$

$A$ company manufactures cassettes. Its cost and revenue functions are $C(x) = 26000 + 30x$ and $R(x) = 43x$,respectively,where $x$ is the number of cassettes produced and sold in a week. How many cassettes must be sold by the company to realize some profit?