480/(5+5+2)=4040*5=20040*7=280荔枝树280棵 龙眼树200棵
设龙眼树x棵,则荔枝树(1+2/5)x棵x+(1+2/5)x=480 12/5x=480 x=200(1+2/5)x=280
荔枝树是336棵,龙眼树是144棵