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

$\left(\frac{2}{5}m^7n\right)\cdot\left(\frac{5}{3}m^3n^6\right)$

$\left(4x+3\right)\left(x-2\right)$

$4+\left(1+1\right)^2\cdot3$

$x+12=9$

$\left(\frac{-9}{\left(x+1\right)^4}\right)+\left(\frac{4}{x+1}\right)$

$3.77\cdot2.125$