作业帮先化简,再求值[(a^3+2a^2+4a)/(a-2)(a^2+2a+4)]-10/(a^2+a-6)除以[1- 21/(a^2-4)]*(a+3)/(a-2),其中a=1/2
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/24 14:25:11
![先化简,再求值[(a^3+2a^2+4a)/(a-2)(a^2+2a+4)]-10/(a^2+a-6)除以[1- 21/(a^2-4)]*(a+3)/(a-2),其中a=1/2](/uploads/image/z/659601-9-1.jpg?t=%E5%85%88%E5%8C%96%E7%AE%80%2C%E5%86%8D%E6%B1%82%E5%80%BC%5B%28a%5E3%2B2a%5E2%2B4a%29%2F%28a-2%29%28a%5E2%2B2a%2B4%29%5D-10%2F%28a%5E2%2Ba-6%29%E9%99%A4%E4%BB%A5%5B1-+21%2F%28a%5E2-4%29%5D%2A%28a%2B3%29%2F%28a-2%29%2C%E5%85%B6%E4%B8%ADa%3D1%2F2)
xŒ1
04
iRKE R"T tuTpA(פE+ DMf'-\4~kH
X ;策m9 Ɏi])T<n($7~n]
OgKKeJ nl*fl 2MpG j0
先化简,再求值[(a^3+2a^2+4a)/(a-2)(a^2+2a+4)]-10/(a^2+a-6)除以[1- 21/(a^2-4)]*(a+3)/(a-2),其中a=1/2
先化简,再求值[(a^3+2a^2+4a)/(a-2)(a^2+2a+4)]-10/(a^2+a-6)除以[1- 21/(a^2-4)]*(a+3)/(a-2),其中a=1/2
先化简,再求值[(a^3+2a^2+4a)/(a-2)(a^2+2a+4)]-10/(a^2+a-6)除以[1- 21/(a^2-4)]*(a+3)/(a-2),其中a=1/2
[(a^3+2a^2+4a)/(a-2)(a^2+2a+4)]-10/(a^2+a-6)除以[1- 21/(a^2-4)]*(a+3)/(a-2)
=[a(a^2+2a+4)/(a-2)(a^2+2a+4)]-10/(a^2+a-6)*[(a^2-4)/(a^2-4)-21]*(a+3)/(a-2)
=a/(a-2)-10/(a+3)(a-2)*[(a-2)(a+2)/(a^2-4)-21]*(a+3)/(a-2)
=a/(a-2)-10(a+2)/(a+3)(a^2+17)*(a+3)/(a-2)
=a/(a-2)-10(a+2)/(a^2+17)(a-2)
=(a(a^2+17)-10(a+2))/(a^2+17)(a-2)
=(a^3+17a-10a-20)/(a^2+17)(a-2)
=(a^3+7a-20)/(a^2+17)(a-2)
=((1/2)^3+7*1/2-20)/((1/2)^2+17)(1/2-2)
=131/207
先化简,再求值.(a+15)(a-3)-(a+4)(2a+4),a=负5
先化简,再求值.3a(2a^2-4a)-2a^2(3a+4).其中a=-1
先化简,再求值（4a+3a^2-3+3a^3)-(-a+4a^3),其中a=-2
先化简,再求值:a(4-1/a)+a/2-a÷1/a-2,其中a=1/3
先化简,再求值:2a/a2-4-1/a-2,其中a=根3--2
先化简,再求值a2-4/a-3×(1-1/a-2);其中,a=-3
先化简,再求值：(a²+a)(a²-5a+6)分之(2a-a²)(a²+4a+3),其中a=4
先化简,再求值.其中a=-2;(3a+1)(2a-3)-(4a-5)(a-4)
先化简,再求值：A-3/2A-4除以(5/(a-2)-a-2),其中a=1
先化简,再求值2a-4分之a-3÷(a-2分之5-a-2),其中a=1
先化简,再求值4a(a+1)-(2a+1)(2a-1),其中a=-3/4
先化简 再求值(1)3a-4a²+7-3a+2a²+5,其中a=-2
先化简,再求值:【a/(a-2)】-【(2a)/(a^2-2a)】-（2/a）.其中a=3/2
先化简,再求值:a/a-3-a+6/a^2-3a-2/a,其中a=3/2
先化简,再求值:a/a-3-a+6/a^2-3a+3/a,其中a=3/2
先化简,再求值：(a/a-2)-(2a/a²-2a)-2/a,其中a=3/2.
先化简,再求值（3a/a-1 - a/a+1)*a^2-1/a,其中a=根号2-2
先化简,再求值：（a/a-2--a/a+2）乘4-a的平方/a,其中a=2012