计算：1.(m+1)(m^4-m³+m²-m+1);2.(a+b)(a-2b)-(a+2b)(a-b)
问题描述：
计算：1.(m+1)(m^4-m³+m²-m+1);2.(a+b)(a-2b)-(a+2b)(a-b)
答
1
m^5-m^4+m^3-m^2+m+m^4-m^3+m^2-m+1=m^5+1
2
a^2-ab-2b^2-a^2-ab+2b^2=-2ab
答
1.原式=m(m^4-m³+m²-m+1)+(m^4-m³+m²-m+1)=m^5+1
2.原式=(a^2-ab-2b^2)-(a^2+ab-2b^2)=-2ab
答
1.(m+1)(m^4-m³+m²-m+1)
=m^5-m^4+m³-m²+m+m^4-m³+m²-m+1
=m^5+1
2.(a+b)(a-2b)-(a+2b)(a-b)
=a²-2ab+ab-2b²-(a²-ab+2ab-2b²)
=a²-ab-2b²-a²-ab+2b²
=-2ab