$$\frac{6m^2-3m}{4m^2-2}$$

$$4m^2-16n^2$$

$$-\frac{\sec\left(x\right)}{\cos\left(x\right)}+\frac{\tan\left(x\right)}{\cot\left(x\right)}=-1$$

$$12x\:+\:18y\:-\:24z$$

$$sin^2x+3cos^2x=0$$

$$-9+\left(4\right)+\left(-12\right)+1$$