$x^2+86x-306+\frac{1296}{x+4}$

$4.24-2.12$

$2x\left(x-5\right)+3x^2\left(x-5\right)$

$-\frac{1}{\cos^2\left(x\right)}-\frac{tan^2\left(x\right)}{cos^2\left(x\right)}=\frac{1}{cos^4}$

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

$-4\left(1\right)^4+14\left(1\right)^2+9$

$\frac{11^{14}}{11^5}$