先化简再求值1。当a=-2时求(a/a+1+1)/(11-3a^2/1-a^2)的值
热心网友
(a/a+1+1)/(11-3a^2/1-a^2)=(a/a+1+1)(1-a^2)/(11-3a^2)=[a(1+a)(1-a)/a+1-a^2]/(11-3a^2)=(a-a^2+1-a^2)/(11-3a^2)=(a+1)/(11-3a^2)当a=-2时 (a+1)/(11-3a^2)=(-2+1)/(11-3*(-2)^2)=-1/(11-12)=-1/-1=1
先化简再求值1。当a=-2时求(a/a+1+1)/(11-3a^2/1-a^2)的值
(a/a+1+1)/(11-3a^2/1-a^2)=(a/a+1+1)(1-a^2)/(11-3a^2)=[a(1+a)(1-a)/a+1-a^2]/(11-3a^2)=(a-a^2+1-a^2)/(11-3a^2)=(a+1)/(11-3a^2)当a=-2时 (a+1)/(11-3a^2)=(-2+1)/(11-3*(-2)^2)=-1/(11-12)=-1/-1=1