$+25-30+48+2-90$

$u^2+34u+289$

$\frac{-6a+4}{2a}$

$f\left(4\right)=4\left(4\right)\frac{-10}{x-2}$

$csc\left(x\right)^4+cot\left(x\right)^4=\frac{1+\cos\left(x\right)^2}{1-\cos\left(x\right)^2}$

$\left(k-4n\right)\left(k+3n\right)$

$\left(18\:\cdot2000\right)\:+\:\left(24\:\cdot2140\right)$