If the point $(a, a)$ is placed between the lines $|x + y| = 4$,then

The set of all real numbers $x$ for which ${x^2} - |x + 2| + x > 0$ is

$A$ 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 maximum value of $x$ in the set $\{x \in R : \sqrt{x+2} > \sqrt{8-x^2}\}$ is:

The region represented by the inequations $2x + 3y \leqslant 18$,$x + y \geqslant 10$,$x \geqslant 0$,$y \geqslant 0$ is

How many points having integer coordinates are there in the feasible region of the inequalities $3x + 4y \leq 12$,$x \geq 0$,and $y \geq 1$?