4x+12≥5x+13

4x + 12 ≥ 5x + 13 ?

$$\begin{array}{rcl}
4x+12 & \ge & 5x+13 \quad | \quad -4x \\
12 & \ge & -4x+5x+13 \\
12 & \ge & x + 13 \quad | \quad -13 \\
-13+12& \ge & x \\
-1 & \ge & x \\
x & \le & -1
\end{array}\\
\boxed{\ x \le -1\ } \quad \small{\text{ or }} \quad \textcolor[rgb]{1,0,0}{x < -1} \quad \small{\text{ and }} \quad \textcolor[rgb]{1,0,0}{ x = -1}$$

x=≥-1

4*-1+12(=8)≥5*-1+13(=8)