(m^2-4)(n^2-9)+24mn
问题描述:
(m^2-4)(n^2-9)+24mn
答
原式=m²n²-4n²-9m²+36+24mn
=(m²n²+12mn+36)-(9m²-12mn+4n²)
=(mn+6)²-(3m-2n)²
=(mn+3m-2n+6)(mn-3m+2n+6)