$$\left(\frac{4}{3}a-\frac{2}{5}x\right)^2$$

$$2^2-13.2+30$$

$$5sen\theta\:\:cos\theta\:+4cos\theta\:=0$$

$$2x^2+x-5=0$$

$$1500\cdot\left(\frac{\sin\left(24\right)+\cos\left(24\right)}{tan\left(33\right)}\right)$$

$$3.14rh+3.14r^{2}$$

$$7x^a-30x^a-42x^a-9x^a+3x^a$$