$-\:\:\frac{9}{5}\:-\:\left[-\:\frac{2}{5}\:+\:\left(-\:\frac{3}{5}\:-\:\frac{1}{5}\right)\:-\:\left(\frac{7}{5}\:-\:\frac{13}{5}\right)\right]\:-\:\frac{1}{5}\:=\:$

$\left(x\:-\:7\right)^2$

$\lim_{x,y\to1,\frac{\pi}{6}}\left(\frac{x\:seny}{x^2+1}\right)$

$\left|\left(+8\right)\left(+4\right)\right|$

$\lim_{x\to\infty}\left(9x\left(ln\left(x+7\right)-ln\left(x\right)\right)\right)$

$5x\:+\:3y\:-\:19\:+\:7x\:+\:2y\:-\:20$

$\left(m^3n^2-4\right)^3$