$\left(\frac{1}{6}x^3-1\right)+\left(x^2-\frac{1}{2}x+\frac{5}{6}\right)+\left(-\frac{1}{3}x^3-\frac{5}{6}x^2+x-\frac{3}{4}\right)$

$sin2a+2sin^2\left(45-a\right)$

$\frac{x^2y}{6}-\frac{5x^3y}{6}+\frac{3x^4y^3}{2}$

$\frac{dy}{dx}=\frac{y-x+1}{y-x-1}$

$-x^2+4x<7$

$5\left(3x-2\right)=35$

$\cos b\left(\sec\left(b\right)-\sin\left(b\right)\cdot\tan\left(b\right)\right)=\cos^2b$