作业帮计算:1/(m²-m)+(m-2)/(2m²-2),并求当m=3时,原式的值还有一题,用两种不同的运算顺序计算[x/（x-2）-x/（x+2）]×[(2-x)/x]急啊，记住，先化简再求值
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/18 14:36:15
![计算:1/(m²-m)+(m-2)/(2m²-2),并求当m=3时,原式的值还有一题,用两种不同的运算顺序计算[x/（x-2）-x/（x+2）]×[(2-x)/x]急啊，记住，先化简再求值](/uploads/image/z/671619-3-9.jpg?t=%E8%AE%A1%E7%AE%97%3A1%2F%28m%26%23178%3B-m%29%2B%28m-2%29%2F%282m%26%23178%3B-2%29%2C%E5%B9%B6%E6%B1%82%E5%BD%93m%3D3%E6%97%B6%2C%E5%8E%9F%E5%BC%8F%E7%9A%84%E5%80%BC%E8%BF%98%E6%9C%89%E4%B8%80%E9%A2%98%2C%E7%94%A8%E4%B8%A4%E7%A7%8D%E4%B8%8D%E5%90%8C%E7%9A%84%E8%BF%90%E7%AE%97%E9%A1%BA%E5%BA%8F%E8%AE%A1%E7%AE%97%5Bx%2F%EF%BC%88x-2%EF%BC%89-x%2F%EF%BC%88x%2B2%EF%BC%89%5D%C3%97%5B%282-x%29%2Fx%5D%E6%80%A5%E5%95%8A%EF%BC%8C%E8%AE%B0%E4%BD%8F%EF%BC%8C%E5%85%88%E5%8C%96%E7%AE%80%E5%86%8D%E6%B1%82%E5%80%BC)
计算:1/(m²-m)+(m-2)/(2m²-2),并求当m=3时,原式的值还有一题,用两种不同的运算顺序计算[x/（x-2）-x/（x+2）]×[(2-x)/x]急啊，记住，先化简再求值
计算:1/(m²-m)+(m-2)/(2m²-2),并求当m=3时,原式的值
还有一题,
用两种不同的运算顺序计算
[x/（x-2）-x/（x+2）]×[(2-x)/x]
急啊，记住，先化简再求值
计算:1/(m²-m)+(m-2)/(2m²-2),并求当m=3时,原式的值还有一题,用两种不同的运算顺序计算[x/（x-2）-x/（x+2）]×[(2-x)/x]急啊，记住，先化简再求值
1/(m²-m)+(m-2)/(2m²-2)
=1/m(m-1)+(m-2)/2(m+1)(m-1)
=[2(m+1)+(m-2)m]/2m(m+1)(m-1)
=(2m+2+m²-2m)/2m(m+1)(m-1)
=(m²+2)/2m(m+1)(m-1)
m=3代入得
(9+2)/(2*3*4*2)
=11/48
先通分再算乘
[x/（x-2）-x/（x+2）]×[(2-x)/x]
=[x(x+2)-x(x-2)]/(x-2)(x+2)×[-(x-2)/x]
=-(x²+2x-x²+2x)/[(x+2)/x]
=-4x/[(x+2)/x]
=-4/(x+2)
直接用分配率
[x/（x-2）-x/（x+2）]×[(2-x)/x]
=x/(x-2)*[(2-x)/x]-x/(x+2)* (2-x)/x
=-1-(2-x)/(x+2)
=(-x-2+x-2)/(x+2)
=-4/(x+2)
将m=3代入
原式=1/6+1/16=11/48先化简再求值，你连化简都没花，直接带进去谁不会！1/(m²-m)+(m-2)/(2m²-2)=1/m(m-1)+m-2/2(m+1)(m-1)=2(m+1)/2m(m+1)(m-1)+(m-2)m/2m(m+1)(m-1)=m²+2/2m(m²-1) 将m=3代入原式=1/6+1/16=1...
全部展开
将m=3代入
原式=1/6+1/16=11/48
收起