\[\ y² + 1 \geq 2 \cdot (5y - 12)\]
\[y^{2} + 1 \geq 10y - 24\]
\[y^{2} - 10y + 25 \geq 0\]
\[(y - 5)^{2} \geq 0 \Longrightarrow ч.т.д.\]
\[x < y\]
\[\ 8x < 8y\]