一间长9米,宽5米,高三米的教室需要粉刷四壁,已知门窗共12平方米,需要粉刷的面积有多大? 一间教室长9米,宽5米,高3米,要粉刷教室的四壁及屋顶(扣除...
\u4e00\u95f4\u957f8\u7c73.\u5bbd6\u7c73.\u9ad82.8\u7684\u6559\u5ba4.\u9700\u8981\u7c89\u5237\u56db\u58c1.\u5df2\u77e5\u95e8\u7a97\u517112\u5e73\u65b9\u7c73,\u9700\u8981\u7c89\u5237\u7684\u9762\u79ef\u6709\u591a\u5c11\u5927\uff1f\uff088\u00d72.8+6\u00d72.8\uff09\u00d72-12
=66.4\u5e73\u65b9\u7c73
\uff081\uff099\u00d75+\uff089+5\uff09\u00d73\u00d72-25.2\uff0c=45+84-25.2\uff0c=103.8\uff08\u5e73\u65b9\u7c73\uff09\uff1b\u7b54\uff1a\u6bcf\u53e3\u6559\u5ba4\u8981\u7c89\u5237\u7684\u9762\u79ef\u662f103.8\u5e73\u65b9\u7c73\uff0e\uff082\uff090.8\u00d7103.8=83.04\uff08\u5343\u514b\uff09\uff1b\u7b54\uff1a\u7c89\u5237\u6bcf\u53e3\u6559\u5ba4\u4e00\u5171\u9700\u8981\u6d82\u659983.04\u5343\u514b\uff0e
9×5+9×3×2+5×3×2-12=45+54+30-12
=117平方米
绛旓細涓闂存暀瀹闀9绫銆佸6绫炽侀珮3绫筹紝瑕佸埛鏁欏鐨勫洓鍛ㄥ拰椤堕儴鎵i櫎闂ㄧ獥鍜岄粦鏉跨殑闈㈢Н25骞虫柟绫筹紝姹傞渶瑕佺矇鍒风殑闈㈢Н鏄灏戝钩鏂圭背锛燂紵锛熷垎鏋愶細鎬婚潰绉=椤堕儴闈㈢Н+鍥涘懆闈㈢Н-25 椤堕儴闈㈢Н=灏好楀 鍥涘懆闈㈢Н=搴曢潰鍛ㄩ暱脳楂=锛堥暱+瀹斤級脳2脳楂 缁煎悎绠楀紡锛9脳6+锛9+6锛壝2脳3-25 =54+90-25 =119骞虫柟绫 绛旓細闇瑕...
绛旓細涓闂存暀瀹ゅ湴闈㈡槸闀9绫,瀹5绫崇殑闀挎柟褰,闈㈢Н鏄灏戝钩鏂圭背?9X5=45骞虫柟绫炽傚鏋滈夌敤50cmx50cm鐨勫湴鐮栭摵杩欓棿鏁欏锛岄渶瑕佺敤澶氬皯鍧楋紵45闄や互锛0.5X0.5锛=45闄や互0.25 =180锛堝潡锛
绛旓細骞冲潎姣忎汉鍗犲湴 =9脳6梅45 =1.2骞虫柟绫 绮夊埛闈㈢Н =搴曢潰绉+渚ч潰绉-24 =9脳6+2脳锛9脳3+6脳3锛-24 =54+90-24 =120骞虫柟绫 ~涓鍒绘案杩523涓轰綘瑙g瓟锛岀浣犲涔犺繘姝~~濡傛灉浣犺鍙垜鐨勫洖绛旓紝璇峰強鏃剁偣鍑汇愰噰绾充负婊℃剰鍥炵瓟銆戞寜閽畘~鎵嬫満鎻愰棶鑰呭湪瀹㈡埛绔笂璇勪环鐐光滄弧鎰忊濆嵆鍙瘇~~浣犵殑閲囩撼鏄垜鍓嶈繘鐨勫姩...
绛旓細9脳6+9脳3脳2+6脳3脳2-19.6 =54+54+36-19.6 =124.4锛堝钩鏂圭背锛夌瓟锛氱矇鍒风殑闈㈢Н鏄124.4骞虫柟绫筹紟
绛旓細0.4脳銆9脳6+2脳(3脳6+3脳9)-25銆=47.6鍗冨厠
绛旓細9鍜6鐨勬渶澶у叕绾︽暟鏄3锛屾渶澶ч夎竟闀3绫=30鍒绫崇殑鏂圭爾瑕佸皬浜10鍒嗙背灏遍夎竟闀6鍒嗙背鐨勬柟鐮栥傚洜涓鸿閫10浠ヤ笅鐨30鐨勫洜鏁
绛旓細澶╄姳鏉匡細12脳5=60骞虫柟绫筹紝鍥涘懆澧欓潰(鍖呮嫭闂ㄧ獥)锛(2脳12+2脳5)脳3=102骞虫柟绫筹紝绮夊埛闈㈢Н锛60+102-9=153骞虫柟绫炽
绛旓細浣犲ソ锛9脳6+9脳4脳2+6脳4脳2-35 =54+72+48-35 =139锛堝钩鏂圭背锛夌瓟锛氱矇鍒风殑闈㈢Н鏄139骞虫柟绫
绛旓細63.7骞崇背宸﹀彸
绛旓細鐢遍鎰忓緱鐭 鏂圭爾杈归暱涓3鍒嗙背=0.3绫 鏂圭爾闈㈢Н涓 0.3脳0.3=0.09锛坢²锛夋椿鍔ㄥ鐨勯潰绉槸 9脳5=45锛坢²锛夋柟鐮栫殑鏁伴噺涓 45梅0.09=500锛堝潡锛夐渶瑕500鍧楁柟鐮