$$\left(\frac{1}{2}a^2-\frac{2}{3}b^3\right)^4$$

$$\sqrt[5]{a^2}\cdot a^{\frac{1}{2}}$$

$$30+x=150$$

$$-7x+x\left(x-2\right)=x^2-7x$$

$$\frac{1-cos^2\left(y\right)}{cos^2\left(y\right)}$$

$$\lim_{x\to\infty}\left(-x\cdot\:cos\left(x\right)+sin\left(x\right)\right)$$