2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)·····先化简再求值:2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)其中a=1+根号2

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/02 07:41:02

2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)·····先化简再求值:2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)其中a=1+根号2
2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)·····
先化简再求值:2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)其中a=1+根号2

2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)·····先化简再求值:2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)其中a=1+根号2
2/(a-2)+(a²-4a+4)/(a²-1)÷(a-2)/(a+1)
=2/(a-2)+(a-2)²/([(a+1)(a-1)]×(a+1)/(a-2)
=2/(a-2)+(a-2)/(a-1)
=[2(a-1)+(a-2)²]/[(a-2)(a-1)]
=[2(1+√2-1)+(1+√2-2)]/[(1+√2-2)(1+√2-1)]
={√2-1)/[(√2-1)×√2]
=(√2)/2

解:原式=2/(a-2)+(a-2)^2÷(a-2)/(a+1)
=2/(a-2)+(a-2)/(a+1)
=[2(a+1)+(a-2)^2]/(a-2)(a+1)
=(2a+2+a^2-2a+4)/(a^2-a-2)
=(a^2+6)/(a^2-a-2)
=(9+2✓2)/(3+2✓2-1-✓2-2)
=9...

全部展开

解:原式=2/(a-2)+(a-2)^2÷(a-2)/(a+1)
=2/(a-2)+(a-2)/(a+1)
=[2(a+1)+(a-2)^2]/(a-2)(a+1)
=(2a+2+a^2-2a+4)/(a^2-a-2)
=(a^2+6)/(a^2-a-2)
=(9+2✓2)/(3+2✓2-1-✓2-2)
=9✓2/2+2

收起