(1)|-1/2|-根号9+(π+4)^0-sin30°+1/(根号2-1)(2)|-2|-4sin45°-(1/2)^(-2)+2根号2-(根号3-根号2)^0(3)求值:(1-1/(a-1))÷(a^2-4a+4)/(a^2-a)其中a=-1(4)先化简再求值:(a^2+6a+9)/(a^2-16)÷(a+3)/(2a-8)-(2a)/(a
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![(1)|-1/2|-根号9+(π+4)^0-sin30°+1/(根号2-1)(2)|-2|-4sin45°-(1/2)^(-2)+2根号2-(根号3-根号2)^0(3)求值:(1-1/(a-1))÷(a^2-4a+4)/(a^2-a)其中a=-1(4)先化简再求值:(a^2+6a+9)/(a^2-16)÷(a+3)/(2a-8)-(2a)/(a](/uploads/image/z/15199062-6-2.jpg?t=%EF%BC%881%EF%BC%89%7C-1%2F2%7C-%E6%A0%B9%E5%8F%B79%2B%28%CF%80%2B4%29%5E0-sin30%C2%B0%2B1%2F%EF%BC%88%E6%A0%B9%E5%8F%B72-1%EF%BC%89%EF%BC%882%EF%BC%89%7C-2%7C-4sin45%C2%B0-%281%2F2%29%5E%28-2%29%2B2%E6%A0%B9%E5%8F%B72-%28%E6%A0%B9%E5%8F%B73-%E6%A0%B9%E5%8F%B72%29%5E0%EF%BC%883%EF%BC%89%E6%B1%82%E5%80%BC%EF%BC%9A%EF%BC%881-1%2F%EF%BC%88a-1%EF%BC%89%EF%BC%89%C3%B7%EF%BC%88a%5E2-4a%2B4%EF%BC%89%2F%EF%BC%88a%5E2-a%29%E5%85%B6%E4%B8%ADa%3D-1%284%29%E5%85%88%E5%8C%96%E7%AE%80%E5%86%8D%E6%B1%82%E5%80%BC%3A%28a%5E2%2B6a%2B9%29%2F%28a%5E2-16%29%C3%B7%28a%2B3%29%2F%282a-8%29-%282a%29%2F%28a)
(1)|-1/2|-根号9+(π+4)^0-sin30°+1/(根号2-1)(2)|-2|-4sin45°-(1/2)^(-2)+2根号2-(根号3-根号2)^0(3)求值:(1-1/(a-1))÷(a^2-4a+4)/(a^2-a)其中a=-1(4)先化简再求值:(a^2+6a+9)/(a^2-16)÷(a+3)/(2a-8)-(2a)/(a
(1)|-1/2|-根号9+(π+4)^0-sin30°+1/(根号2-1)
(2)|-2|-4sin45°-(1/2)^(-2)+2根号2-(根号3-根号2)^0
(3)求值:(1-1/(a-1))÷(a^2-4a+4)/(a^2-a)其中a=-1
(4)先化简再求值:(a^2+6a+9)/(a^2-16)÷(a+3)/(2a-8)-(2a)/(a+4),其中a=2
(5)因式分解(1)9x^2-y^2-4y-4(2)2a^2-4a+2
(1)|-1/2|-根号9+(π+4)^0-sin30°+1/(根号2-1)(2)|-2|-4sin45°-(1/2)^(-2)+2根号2-(根号3-根号2)^0(3)求值:(1-1/(a-1))÷(a^2-4a+4)/(a^2-a)其中a=-1(4)先化简再求值:(a^2+6a+9)/(a^2-16)÷(a+3)/(2a-8)-(2a)/(a
(1)|-1/2|-根号9+(π+4)^0-sin30°+1/(根号2-1)
=1/2-3+1-1/2+根号2+1
=根号2-1
(2)|-2|-4sin45°-(1/2)^(-2)+2根号2-(根号3-根号2)^0
=2-2√2-√2+2√2-1
=-1
(3)求值:(1-1/(a-1))÷(a^2-4a+4)/(a^2-a)其中a=-1
=(a-2)/(a-1)×a(a-1)/(a-2)²
=a/(a-2)
代入a=-1,-1/(-1-2)=1/3
(4)先化简再求值:(a^2+6a+9)/(a^2-16)÷(a+3)/(2a-8)-(2a)/(a+4),其中a=2
=(a+3)²/(a-4)(a+4)×2(a-4)/(a+3)-2a/(a+4)
=2(a+3)/(a+4)-2a/(a+4)
=6/(a+4)
代入a=2得6/(a+4)=1
(5)因式分解
(1)9x^2-y^2-4y-4
=(3x)^2-(y+2)^2
=(3x-y-2)(3x+y+2)
(2)2a^2-4a+2
=2(a^2-2a+1)
=2(a-1)^2
(1)|-1/2|-根号9+(π+4)^0-sin30°+1/(-1)
=1/2-3+1-1/2+根号2 +1
=-1+根号2
(2)|-2|-4sin45°-(1/2)^(-2)+2根号2-(根号3-根号2)^0
=2-2根号-4+2根号2-1
=-3
(3)求值:(1-1/(a-1))÷(a^2-4a+4)/(a^2-a)其中a=-1
全部展开
(1)|-1/2|-根号9+(π+4)^0-sin30°+1/(-1)
=1/2-3+1-1/2+根号2 +1
=-1+根号2
(2)|-2|-4sin45°-(1/2)^(-2)+2根号2-(根号3-根号2)^0
=2-2根号-4+2根号2-1
=-3
(3)求值:(1-1/(a-1))÷(a^2-4a+4)/(a^2-a)其中a=-1
(a-2)/(a-1)*a(a-2)/(a-2)^2
=a/[(a-1)
=1/2
(4)先化简再求值:(a^2+6a+9)/(a^2-16)÷(a+3)/(2a-8)-(2a)/(a+4),其中a=2
(a+3)^2/[(a+4)(a-4)]*2(a-4)/(a+3)-2a/(a+4)
=2(a+3)/(a+4)-2a/(a+4)
=6/(a+4)
=1
(5)因式分解9x^2-y^2-4y-4(2)2a^2-4a+2
9x^2-y^2-4y-4
=(3x)^2-(y+2)^2
=(3x+y+2)(3x-y-2)
2a^2-4a+2
=2(a^2-2a+1)
=2(a-1)^2
收起
(1) 跟号2-1
(2)-3
(3)1/3
(4)6/(a+4)=1
(5) 1.。。(3x-y-2)(3x+y+2) 2.........2(a-1)^2