若(log23)x-(log53)x≥(log23)-y-(log53)-y,则( ).则( ).(A)x-y≥0 (B)x+y≥_数学解答

若(log23)x-(log53)x≥(log23)-y-(log53)-y,则( ).
则( ).
(A)x-y≥0 (B)x+y≥0 (C)x-y≤0 (D)x+y≤0

人气：109 ℃　时间：2020-05-08 06:05:37

解答

将左边的移到右边得:(log23)x-(log23)-y-(log53)x+(log53)-y≥0{(log23)x-(log23)-y}-{(log53)x-(log53)-y}≥0底数相同,指数相加减.这儿是减就用减.(log23){x-(-y)}-(log53){x-(-y)}≥0(log23)(x+y)-(log53)(x+y)≥0...