$$\frac{x}{3}+\frac{x}{6}\ge \frac{x}{4}+230 |·12$$

$$\frac{12·x}{3}+\frac{12·x}{6}\ge \frac{12·x}{4}+12·230$$

$$\frac{4·\bcancel{3}·x}{\bcancel{3}}+\frac{2·\bcancel{6}·x}{\bcancel{6}}\ge \frac{3·\bcancel{4}·x}{\bcancel{4}}+12·230$$

$$4x+2x\ge 3x+2760$$

$$4x+2x-3x\ge 2760$$

$$3x\ge 2760$$

$$x\ge \frac{2760}{3}$$

$$x\in \left\{920, 921, 922, .... 998, 999\right\}$$

$$3·4^x+4^{x+1}=896$$

$$3·4^x+4^x·4^1=896$$

$$7·4^x=896$$

$$4^x=\frac{896}{7}$$

$$4^x=128$$

$${\left(2^2\right)}^x=2^7$$

$$2^{2x}=2^7$$

$$2x=7$$