(m-5n)(m-n)-6(m+2n)(m-3n)
问题描述:
(m-5n)(m-n)-6(m+2n)(m-3n)
计算,要有过程
答
原式=(m²-mn-5mn+5n²)-6(m²-3mn+2mn-6n²)=(m²-6mn+5n²)-6(m²-mn-6n²)=m²-6mn+5n²-6m²+6mn+36n²=-5m²+41n²