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

$-7n-7-9+10n$

$\sqrt{15^2+26^2}$

$\left(\left(\left(-13^2\left(-13^9\right)^4\right)^{\frac{1}{5}}\right)^{\frac{1}{2}}\right)^{\frac{1}{3}}$

$20r^2\:+\:45r^3$

$9x^2=36x-18$

$\frac{3}{2}=\sin\left(x\right)\cdot\cos\left(x\right)$