Выражения: а)(2m-3n)(5m+n)-10(m+n)^2 )^3*(-2a^5b)^2

A)2m*5m-3n*5m+2m*n-3n*n-10*(m^2+2mn+n^2)=10m^2-15mn+2mn-3n^2-10m^2-20mn-10n^2=-33mn-13n^2
b)...=(-3)^3 *(a^2)^3  *(b^3)^3  * (-2)^2 *(a^5)^2 *b^2=-27a^6 b^9 *4a^10 b^2=-27*4 *a^16 *b^11=-108a^16 b^11