初二配方法(快,做得好加100分)

来源：百度知道 编辑：UC知道 时间：2024/09/20 16:36:43
1.10m^2-21m+2
2.6y^2+y-35
3.8t^2-22t+15
4.用因式分解:
a^4-4a^3+4a^2-9
要详细过程 ,快,追加100,只要过程

1.(10m-1)(m-2)
2.(2y+5)(3y-7)
3.(4t-5)(2t-3)
4.原式=a^4-3a^3-a^3+3a^2+a^2-3a+3a-9
=a^3(a-3)-a^2(a-3)+a(a-3)+3(a-3)
=(a-3)(a^3-a^2+a+3)
=(a-3)(a^3+a^2-2a^2-2a+3a+3)
=(a-3)(a+1)(a^2-2a+3)

1.(10m-1)(m-2)
2.(2y+5)(3m-7)
3.(2t-3)(4t-5)
4.不会。

这还要详细过程。配方都不会啊。

(10m-1)*(m-2)
(2y+5)*(3y-7)
(2t-3)*(4t-5)
(a-3)(a+1)(a^2-2a+3)

1.10m^2-21m+2=(10m-1)(m-2)

2.6y^2+y-35=(2y+5)(3y-7)

3.8t^2-22t+15=(2t-3)(3t-5)

4.用因式分解:
a^4-4a^3+4a^2-9 =a^2(a^2-4a-4)-9=a^2(a-2)^2-9
=[a(a-2)-3]*[a(a-2)+3]
=(a-3)(a+1)(a^2-2a+3)

a^4-4a^3+4a^2-9 =（a^2-2a+3)(a+1)(a-3)

1.10m^2-21m+2 ＝(10m-1)(m-2)

2.6y^2+y-35＝(2y+5)(3y-7)

3.8t^2-22t+15＝(2t-3)(4t-5)

4.用因式分解:
a^4-4a^3+4a^2-9
＝a^2(a^2-4a+4)-9
=a^2(a-2)^2-9
=(a(a-2)+3)(a(a-2)-3)
=(a^2-2a+3)(a^2-2a-3)
=(a^2-2a+3)(a-3)(a+1)