25(3m–2n)∧2–9(m+4n)∧2

问题描述:

25(3m–2n)∧2–9(m+4n)∧2

原式=25(9m^2-12mn+4n^2)-9(m^2+8mn+16n^2)
=175m^2-300mn+100n^2-9m^2-72mn-144n^2
=166m^2-372mn-44n^2
这个式子没法因式分解的