初一数学计算题(过程稍微详细点)

来源:百度知道 编辑:UC知道 时间:2024/06/15 20:32:01
(1).(x+y)(a+2b)

(2).(2a+3)(2/3b+5)

(3).(2x+3)(-x-1)

(4).(-2m-1)(3m-2)

(5).(x-y)^2

(6).(-2x+3)^2

(1).(x+y)(a+2b)
=ax+2bx+ay+2by

(2).(2a+3)(2/3b+5)
=4/3ab+10a+2b+15

(3).(2x+3)(-x-1)
=-2x^2-2x-3x-3
=-2x^2-5x-3

(4).(-2m-1)(3m-2)
=-6m^2+4m-3m+2
=-6m^2+m+2

(5).(x-y)^2
=x^2-2xy+y^2

(6).(-2x+3)^2
=4x^2-12x+9

……介个,还要过程,不是罢……

(1).(x+y)(a+2b)=x*a+x*2b+a*y+a*2b=ax+ay+2bx+2by
(2).(2a+3)(2/3b+5)=4/3ab+10a+2b+15
(3).(2x+3)(-x-1)=2x的平方-2x-3x-3=-2x的平方-5x-3
(4).(-2m-1)(3m-2)=-6m的平方-4m-3m+2=-6m的平方-7m+2
^是什么意思?