(a^2+7a+10)/(a^2-a+1)*(a^4+a)/(a^2+4a+3)/(a^2+a)/(a+2)当a=-1时,化简求值

问题描述:

(a^2+7a+10)/(a^2-a+1)*(a^4+a)/(a^2+4a+3)/(a^2+a)/(a+2)当a=-1时,化简求值

=(a+2)(a+5)/(a^2-a+1) *a(a+1)(a^2-a+1)/(a+3)(a+1) *(a+2)/a(a+1)
=(a+2)^2(a+5) /(a+3) (a+1)