不要超范围,第五题中的一和三
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不要超范围,第五题中的一和三
![](http://img.wesiedu.com/upload/b/17/b17e7eda52b399e3d3d55376af0576a4.jpg)
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![不要超范围,第五题中的一和三](/uploads/image/z/19478129-41-9.jpg?t=%E4%B8%8D%E8%A6%81%E8%B6%85%E8%8C%83%E5%9B%B4%2C%E7%AC%AC%E4%BA%94%E9%A2%98%E4%B8%AD%E7%9A%84%E4%B8%80%E5%92%8C%E4%B8%89)
(1)化简:
= m(m-n)/(m+n)(m-n) + m(m+n)/(m+n)(m-n) - n²/(m+n)(m-n)
= m(m-n)+m(m+n)-n²/(m+n)(m-n)
= m²-mn+m²+mn-n²/(m+n)(m-n)
= 2m²-n²/m²-n² < 话说到这就化简不了了...好复杂的算式>-< >
∵m/n=5/3
∴m=5,n=3
将m=5,n=3代入:
= 2×25-9/25-9
= 41/16
(2)化简:
3x-4/(x-1)(x-2) = a(x-2)/(x-1)(x-2) + b(x-1)/(x-1)(x-2)
3x-4/(x-1)(x-2) = a(x-2)+b(x-1)/(x-1)(x-2)
3x-4/(x-1)(x-2) = ax-2a+bx-b/(x-1)(x-2)
∵ax+bx = 3x,
-2a-b = -4,
a、b为实数
∴a=1,b=2
sorry~算得太久了,不知道耽误了没有...(算了20多分钟...Q-Q)我也是初二的哦~
= m(m-n)/(m+n)(m-n) + m(m+n)/(m+n)(m-n) - n²/(m+n)(m-n)
= m(m-n)+m(m+n)-n²/(m+n)(m-n)
= m²-mn+m²+mn-n²/(m+n)(m-n)
= 2m²-n²/m²-n² < 话说到这就化简不了了...好复杂的算式>-< >
∵m/n=5/3
∴m=5,n=3
将m=5,n=3代入:
= 2×25-9/25-9
= 41/16
(2)化简:
3x-4/(x-1)(x-2) = a(x-2)/(x-1)(x-2) + b(x-1)/(x-1)(x-2)
3x-4/(x-1)(x-2) = a(x-2)+b(x-1)/(x-1)(x-2)
3x-4/(x-1)(x-2) = ax-2a+bx-b/(x-1)(x-2)
∵ax+bx = 3x,
-2a-b = -4,
a、b为实数
∴a=1,b=2
sorry~算得太久了,不知道耽误了没有...(算了20多分钟...Q-Q)我也是初二的哦~