$4f+6f$

$f\left(x\right)=\frac{1000}{5\cdot1245\cdot e^0}$

$f\left(x\right)=\sqrt{\left(\frac{2x-3}{x+1}+1\right)}$

$\int_{-\infty\:}^{6.44}0,19947\cdot e^{-\frac{x^2}{8}}dx$

$15\:-\:13z\:-\:16\:+\:12z\:-\:3z^2\:+\:z^2\:-\:10$

$\left(x^5-y^3\right)\left(x^{10}-x^5y^3+y^6\right)$

$-4=9+y$