$-cot\left(x\right)-1=0$

$-\left(-\frac{1}{3}+\frac{5}{3}y\right)$

$\int_{-4}^5\left(8y^2+12y^2+9\right)dy$

$\frac{81}{x^3}-1=2$

$\lim_{x\to\:0}\:\frac{\left(6\sin\left(x\right)cos\left(x\right)-x\right)}{tan\left(x\right)-x}$

$x^2+-y^2+2x^2-x^2+y^2$

$\frac{6.5-4}{9-4}$