\(B=\frac{3^9-2^3\cdot3^7+2^{10}\cdot3^2-2^{13}}{3^{10}-2^2\cdot3^7+2^{10}\cdot3^3-2^{12}}\)
\(B=\frac{1-2\cdot1+1\cdot1-2}{3-1\cdot1+1\cdot3-1}\)
\(B=\frac{1-2+1-2}{3-1+3-1}\)
\(B=\frac{-1+\left(-1\right)}{2+2}\)
\(B=\frac{-2}{4}\)
\(\Rightarrow B=\frac{-1}{2}\)