$1-\cos\left(2x\right)=2\sin\left(x\right)^2$

$3a^2b+21ab-54b$

$\lim_{x\to\infty}\left(x\left(ln\left(x\right)-ln\left(x+17\right)\right)\right)$

$\frac{18x^2y^5}{6xy^2}$

$\left(-8\right)-\left(-5\right)-\left(-6\right)$

$\left(12d^{4^7}\right)^2$

$x y ^ { 2 } - x ^ { 2 } + 4 = 0$