化简后求值[(a+3)/(a^2-4)+a/(6-a-a^2)]除以(4a+9)/(5a-10),其中a=-8
问题描述:
化简后求值[(a+3)/(a^2-4)+a/(6-a-a^2)]除以(4a+9)/(5a-10),其中a=-8
答
带进去算不就行了
答
[(a+3)/(a^2-4)+a/(6-a-a^2)]除以(4a+9)/(5a-10)先化简= [(a+3)/(a+2)(a-2)]-a/(a+3)(a-2)除以(4a+9)/(5a-10)通分 (a+2)(a-2)(a+3)=[(a+3)^2 - a(a+2)]/(a+2)(a-2)(a+3)除以(4a+9)/(5a-10)先化简,再约分 =(...