$3x-12-2x\left(x+12\right)$

$\frac{\sec\left(x\right)\csc\left(x\right)}{\cot\left(x\right)}=\sec^2x$

$\left(5\left(1.70\right)+8\right)$

$\frac{u^2}{\left(\left(3+u^2\right)\cdot\left(1+u^2\right)^2\right)}$

$\sqrt[5]{7^2\cdot5}\cdot\sqrt[5]{8.3^2}.\sqrt[15]{24\cdot3\cdot5}$

$1,6x\:-\frac{2}{5}x$

$\int\frac{x^2+3x-2}{\sqrt{x}}dx$