$$4\left(10-3\right)+5\left(15+6\right)$$

$$(\frac{2x}{3}+7y)$$

$$23\cdot39$$

$$\lim_{x\to\infty}\left(\frac{4ln\left(x^3\right)}{\sqrt{x}}\right)$$

$$\cos^2x+2\cos x=0$$

$$\int_{-1}^2\left(2x+1\right)dx$$

$$\left(x+ab\right)^3$$