$3\left(-2\right)^2+15\left(-2\right)+18$

$\int xe^{-ax}dx$

$\left(2+x\right)\:\frac{dy}{dx}\:=\:3y$

$f\left(x\right)=7\left(x+8\right)-7$

$\left(1-\sin^2\left(80\right)\right)\left(1+\tan^2\left(80\right)\right)=1$

$2\left(n+5\right)=-2$

$\left(+8\right).\left(-10\right).\left(+5\right).\left(-1\right)$