\(A=\left(-3\right)\times9\times\left(-8\right)\times5^6=3\times9\times8\times5^6=3^3\times2^3\times5^6\).
\(B=2+2+2^2+2^3+...+2^{11}\)
\(2B=2^2+2^2+2^3+2^4+...+2^{12}\)
\(2B-B=\left(4+2^2+2^3+2^4+...+2^{12}\right)-\left(2+2+2^2+2^3+...+2^{11}\right)\)
\(B=2^{12}\)