市区建住宅小区，已经盖好了13栋楼，还有7栋楼没盖，此住宅区计划一共盖多少栋楼？8?(]9U,}'_4s;d0p/^
算式：提示7M,t-P,s1_'d-H4V3v+@2F8?(]9U,}'_4s;d0p/^
答：此住宅区计划一共盖8X2M)T:l栋楼。8?(]9U,}'_4s;d0p/^