\(A=\frac{a^{2}+a}{a^{2}-4}\frac{a+2}{a+1}\)
\(B=\frac{a^{2}-2ab+b^{2}}{a^{2}-ab+b^{2}}\frac{a^{3}+b^{3}}{(a-b)^{3}}\)
\(Γ=\frac{χ^{2}-3χ+2}{χ^{2}-χ}\frac{χ^{2}+2χ}{χ^{2}+χ-2}\)
\(Δ=\left ( \frac{1}{χ+1}+\frac{1}{1-χ}-\frac{2χ}{1-χ^{2}} \right )\left ( χ+1 \right )\)