TeX джерело:

1)\quad \frac{\begin{array}{l}3 > 2\\\;\; + \\7 > 1\end{array}}{\begin{array}{l}3 + 7 > 2 + 1\\\;\;\;10 > 3\end{array}};\quad 2)\quad \frac{\begin{array}{l}18 < 21\\\quad + \\17 < 20\end{array}}{\begin{array}{l}18 + 17 < 21 + 20\\\;\quad \;\;35 < 41\end{array}};\quad 3)\quad \frac{\begin{array}{l} - 1 < 6\\\quad \; + \\ - 7 < - 6\end{array}}{\begin{array}{l} - 1 - 7 < 6 - 6\\\quad \; - 8 < 0\end{array}}