已知m,n为实数,若不等式(2m-n)x+3m-4n(4/9),求不等式(m-4n)x+2m-3n>0的答案为x>-(1/4)
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![已知m,n为实数,若不等式(2m-n)x+3m-4n(4/9),求不等式(m-4n)x+2m-3n>0的答案为x>-(1/4)](/uploads/image/z/3792539-11-9.jpg?t=%E5%B7%B2%E7%9F%A5m%2Cn%E4%B8%BA%E5%AE%9E%E6%95%B0%2C%E8%8B%A5%E4%B8%8D%E7%AD%89%E5%BC%8F%EF%BC%882m-n%EF%BC%89x%2B3m-4n%EF%BC%884%2F9%EF%BC%89%2C%E6%B1%82%E4%B8%8D%E7%AD%89%E5%BC%8F%EF%BC%88m-4n%EF%BC%89x%2B2m-3n%3E0%E7%9A%84%E7%AD%94%E6%A1%88%E4%B8%BAx%3E-%EF%BC%881%2F4%EF%BC%89)
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已知m,n为实数,若不等式(2m-n)x+3m-4n(4/9),求不等式(m-4n)x+2m-3n>0的答案为x>-(1/4)
已知m,n为实数,若不等式(2m-n)x+3m-4n(4/9),求不等式(m-4n)x+2m-3n>0的
答案为x>-(1/4)
已知m,n为实数,若不等式(2m-n)x+3m-4n(4/9),求不等式(m-4n)x+2m-3n>0的答案为x>-(1/4)
∵不等式(2m-n)x+3m-4n(4/9),
∴(2m-n)x+3m-4n0的解为x>-1/4.
由题意: (2m-n)x+3m-4n<0
(2m-n)x<4n-3m
要解集为x>4/9
那么 2m-n<0
x>(4n-3m)/(2m-n)
所以 4/9=(4n-3m)/(2m-n)
m=8n/7
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由题意: (2m-n)x+3m-4n<0
(2m-n)x<4n-3m
要解集为x>4/9
那么 2m-n<0
x>(4n-3m)/(2m-n)
所以 4/9=(4n-3m)/(2m-n)
m=8n/7
又 2m-n<0
所以 n<0
(m-4n)x+2m-3n>0化为:
-20nx/7-5n/7>0
即: 20x+5>0
x>-1/4
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