先化简再求值 (1+x)分之(x²+2x)÷{x-(x+1)分之2}-1,其中x=根号2+1分之1
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先化简再求值 (1+x)分之(x²+2x)÷{x-(x+1)分之2}-1,其中x=根号2+1分之1
先化简再求值 (1+x)分之(x²+2x)÷{x-(x+1)分之2}-1,其中x=根号2+1分之1
先化简再求值 (1+x)分之(x²+2x)÷{x-(x+1)分之2}-1,其中x=根号2+1分之1
x=1/(√2+1)=√2-1
原式=x(x+2)/(x+1)÷(x²+x-2)/(x+1)-1
=x(x+2)/(x+1)*(x+1)/(x+2)(x-1)-1
=x/(x-1)-1
=(x-x+1)/(x-1)
=1/(x-1)
=1/(√2-1-1)
=(√2+2)/(2-4)
=-(√2+2)/2
您好:
(x²+2x)/(1+x)÷{x-2/(x+1)}-1
=x(x+2)/(x+1) ÷[(2x+2-2)]/(x+1) -1
=x(x+2)/(x+1)÷ 2x/(x+1)-1
=(x+2)/2-1
=1/2x+1-1
=1/2x
=1/2*1/(√2+1)
=1/2*(√2-1)/(√2+1)(√2-...
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您好:
(x²+2x)/(1+x)÷{x-2/(x+1)}-1
=x(x+2)/(x+1) ÷[(2x+2-2)]/(x+1) -1
=x(x+2)/(x+1)÷ 2x/(x+1)-1
=(x+2)/2-1
=1/2x+1-1
=1/2x
=1/2*1/(√2+1)
=1/2*(√2-1)/(√2+1)(√2-1)
=1/2(√2-1)/(2-1)
=1/2(√2-1)
不明白,可以追问如有帮助,记得采纳,谢谢 祝学习进步!
收起
原式=x(x+2)/(x+1)÷[(x+2)(x-1)/(x+1)]-1=x/(x-1)
x=1/(√2+1)=√2-1
原式=(√2-1)/(√2-2)=-√2/2