长方形周长36厘米，宽匕长短4厘米，求宽和长各多少？要有过程。三年级的题目。
\u4e00\u4e2a\u957f\u65b9\u5f62\u7684\u9762\u79ef\u662f36\u5e73\u65b9\u5206\u7c73\uff0c\u957f\u548c\u5bbd\u7684\u957f\u5ea6\u90fd\u662f\u6574\u5398\u7c73\u6570\u3002\u8fd9\u4e2a\u957f\u65b9\u5f62\u5468\u957f\u6700\u957f\u662f\u591a\u5c11\u5398\u7c73\uff1f\u8bbe\u957f\u4e3aX\uff0c\u5bbd\u4e3aY
XY=3600cm2
\u6c422\uff08X+Y\uff09\u6700\u5927\u503c
X+Y>=2*\u6839\u53f7\u4e0b\uff08XY\uff09 \u8fd9\u662f\u516c\u5f0f
\u6240\u4ee5X+Y>=120 X=Y=60cm \u76f8\u5dee\u6700\u5c0f\u65f6 \u5468\u957f\u6700\u5c0f \u6240\u4ee5\u76f8\u5dee\u6700\u5927 \u5468\u957f\u6700\u5927
\u8fd8\u8981\u662f\u6574\u6570\u5398\u7c73 \u6240\u4ee5\u4e00\u4e2a1cm \u4e00\u4e2a3600cm
\u5468\u957f\u6700\u5927\u65f67202cm
\u3002\u3002\u3002\u3002\u522b\u626d\u5462\u3002\u3002\u3002\u3002
\u697c\u4e0a\u7684\u51e0\u4f4d\u662f\u5f53\u6210\u6574\u6570\u5206\u7c73\u505a\u7684\u4e86\u5427\uff1f
\u6211\u4e5f\u6709\u70b9\u8499\u4e86\u5475\u3002\u3002\u3002
\u6bcf\u8fb9\u5e73\u5747\u957f\u5ea6\u4e3a\uff1a36/4=9\u5398\u7c73
\u5bbd\u6bd4\u957f\u77ed4\u5398\u7c73\uff0c\u90a3\u4e48\u957f\u52a02\u5bbd\u51cf2\u5c31\u53ef\u4ee5\u4e86\uff1a
\u957f\uff1a9+2=11\u5398\u7c73\uff0c
\u5bbd\uff1a9-2=7\u5398\u7c73\uff0c
\u6240\u4ee5\u8fd9\u4e2a\u957f\u65b9\u5f62\u7684\u957f\u548c\u5bbd\u5206\u522b\u4e3a11\u548c7\u5398\u7c73\u3002
列个方程，so～easy～
绛旓細瀹芥槸:锛36涓4x2锛壝4 =28梅4 =7锛鍘樼背锛夐暱=7+4=11锛堝帢绫筹級
绛旓細璁闀挎柟褰鐨勫鏄痻鍘樼背锛屽垯闀垮氨鏄痻+4鍘樼背锛屾牴鎹鎰忓彲寰楁柟绋嬶細2锛坸+x+4锛=36 2x+4=18 2x=14 x=77+4=11锛堝帢绫筹級绛旓細闀挎柟褰㈢殑闀挎槸11鍘樼背锛屽鏄7鍘樼背锛
绛旓細璁瀹藉害涓簒鍘樼背锛闀垮害鏄痻+4鍘樼背 x+x+4=36梅2 2x+4=18 2x=14 x=7 瀹7鍘樼背 闀7+4=11鍘樼背
绛旓細璁闀挎柟褰鐨勫鏄痻鍘樼背锛屽垯闀垮氨鏄痻+4鍘樼背锛屾牴鎹鎰忓彲寰楁柟绋嬶細2锛坸+x+4锛=36 2x+4=18 2x=14 x=7 7+4=11锛堝帢绫筹級绛旓細闀挎柟褰㈢殑闀挎槸11鍘樼背锛屽鏄7鍘樼背锛
绛旓細瑙ｄ緷棰樻剰寰 (36梅2-4)梅2 =(18-4)梅2 =14梅2 =7 7+4=11 绛旈暱鏄11cm锛屽鏄7cm銆
绛旓細瀹藉拰闀垮叡鏄36梅2=18鍘樼背 闀挎槸18梅2+4梅2=11鍘樼背 瀹芥槸18-11=7鍘樼背
绛旓細鍋囪瀹戒负x鍘樼背锛鍒欓暱灏变负锛坸+4锛夊帢绫筹紝鎵浠2*x+2*(x+4)=36,瑙ｅ嚭x=7(鍘樼背)
绛旓細闀夸负11锛屽涓7.绠鍗曞拰宸棶棰樸傚崐鍛ㄩ暱鍗抽暱鍔犲36/2=18cm锛闀夸负锛18+4锛/2=11锛屽涓7
绛旓細鏄鍛ㄩ暱鈥濅箞锛 瑙ｇ瓟濡備笅锛氳瀹戒负x cm锛岄暱涓猴紙4+x锛塩m. 鍒2锛坸+4+x锛=36 瑙ｅ緱x=7 4+x=11 鎵浠ラ暱涓11cm锛屽涓7cm.
绛旓細闀挎柟褰鐨鍛ㄩ暱绛変簬锛堥暱鍔犲锛壝2 鍒楁柟绋 锛圶+4+X锛壝2=36 锛2 X+4锛壝2=36 4 X+8=36 4 X=36-8 4 X=28 X=28梅4 X=7 闀挎柟褰㈢殑瀹芥槸7鍘樼背锛閭ｄ箞瀹冪殑闀垮氨鏄7+4=11鍘樼背 涔熷彲浠ヤ笉鐢ㄦ柟绋嬶紝鐩存帴鏍规嵁闀挎柟褰㈢殑鍛ㄩ暱鏄36鍘樼背 閭ｄ箞闀挎柟褰㈢殑闀垮姞瀹界瓑浜36梅2=18 瀹芥瘮闀跨煭4鍘樼背 鐢18-4梅...
