兔:x只,鸡比兔多24只,鸡:x+24只
4x+2(x+24)=138
4x+2x+48=138
6x=90
x=15
鸡比兔多24只,鸡15+24=39只 兔:x只,鸡比兔多24只,鸡:x+24只
4x+2(x+24)=138
4x+2x+48=138
6x=90
x=15
鸡比兔多24只,鸡15+24=39只