﹙1﹚﹙2x﹚³·﹙－5xy²﹚ ﹙2﹚﹙2／3ab²-2ab﹚·1／2ab

题目

﹙1﹚﹙2x﹚³·﹙－5xy²﹚ ﹙2﹚﹙2／3ab²-2ab﹚·1／2ab
﹙3﹚﹙-3x+2﹚﹙3x+2﹚ ﹙4﹚﹙-28a³-14a²+a﹚÷﹙-7a﹚
﹙5﹚﹙x-1﹚²-﹙x+5﹚﹙x-1﹚

答案

1.=8*(-5)*(x^4)*(y^2)
=-40(x^4)(y^2){不方便打指数,直接写时去括号.}
2.=(1/3)b-1
3.=2^2-(3x)^2
=4-9x^2
4.=-7a(4a^2+14a-1)/(-7a)
=4a^2+14a-1
5.=(x-1-x-5)(x-1)
=-6x+6