若m-1/m=-1,求2m²+2m-3的值?若2m²-3m+1=0,求2m+1/m的值?
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![若m-1/m=-1,求2m²+2m-3的值?若2m²-3m+1=0,求2m+1/m的值?](/uploads/image/z/2587152-48-2.jpg?t=%E8%8B%A5m-1%EF%BC%8Fm%3D-1%2C%E6%B1%822m%26%23178%3B%2B2m-3%E7%9A%84%E5%80%BC%3F%E8%8B%A52m%26%23178%3B-3m%2B1%3D0%2C%E6%B1%822m%2B1%EF%BC%8Fm%E7%9A%84%E5%80%BC%3F)
若m-1/m=-1,求2m²+2m-3的值?若2m²-3m+1=0,求2m+1/m的值?
若m-1/m=-1,求2m²+2m-3的值?若2m²-3m+1=0,求2m+1/m的值?
若m-1/m=-1,求2m²+2m-3的值?若2m²-3m+1=0,求2m+1/m的值?
m-1/m=-1
两边乘m
m²-1=-m
m²+m=1
所以原式=2(m²+m)-3
=2-3
=-1
2m²-3m+1=0
2m²+1=3m
显然m=0代入不成立
所以m≠0
所以两边除以m
2m+1/m=3