x>1,x-1>0,当x变大,1/(x-1)变小,而-1/(x-1)变大,∴f(x)是增函数
1)f(2t-3)>f(4-t)等价于2t-3>4-t>0,解得7/31,∴a≠1,a=1-(1/m)
m>1时,有0