$2^2-\left(-1\right)^4$

$\left(c+d-1\right)\left(a^2+c+1\right)-c^2-1$

$-\frac{5}{6}a^{x+1}+\frac{3}{4}a^{x+1}$

$\lim_{x\to2}\left(\frac{x^3-6x^2+12x-8}{\left(x-2\right)^2}\right)$

$3\cdot\log_x\left(3\right)-\log_x\left(9\right)=2$

$\cos\left(2x\right)-11\cos\left(x\right)+6=0$

$\int x^2cos\left(2x^3\right)dx$