计划购买甲，乙两种树苗n棵，甲树苗50元一棵成活率90%，乙树苗80元一棵成活率95%。
\u4e03\u5e74\u7ea7\u6570\u5b66\u5173\u4e8e\u4e70\u6811\u82d7\u7684\u4e60\u9898\u753250\u5143\u4e00\u68f5\uff0c\u4e5980\u5143\u4e00\u68f5\uff0c\u7532\u6210\u6d3b\u738790%\u4e59\u6210\u5047\u8bbe\u7528\u7532x\u682a\uff0c\u5219\u4e59\u4e3ay\uff0c26000\uff1d50x\uff0b80y\uff0cx\u25710.9\uff0by\u25710.95\uff1dn \u7136\u540e\u8054\u7acb\u89e3\u65b9\u7a0b\u7b54\u6848\u5c31\u51fa\u6765\u4e86
\u8fd9\u4e2a\u662f\u4e00\u5143\u4e00\u6b21\u51fd\u6570\u7684\u5e94\u7528 \u8be6\u89e3\u5982\u4e0b\uff1a
\u2264\u2265\uff0b\uff0d\u00d7\uff1d
\u8bbe\u8d2d\u4e70\u7532\u6811\u82d7x\u682a\uff0c\u5219\u4e70\u4e59\u6811\u82d7\u4e3a\uff08500-x\uff09\u682a\uff0cx\u7684\u521d\u6b65\u8303\u56f4\u786e\u5b9a\u4e3a 1\u2264x\u2264500\u4e14\u60f3x\u5c5e\u4e8e\u6574\u6570\uff08\u8fd9\u91cc\u5f97\u5199\u6210\u6570\u5b66\u8bed\u8a00\uff0c\u6ca1\u6709\u516c\u5f0f\u7f16\u8f91\u5668\uff0c\u6240\u4ee5\u5199\u6210\u767d\u8bdd\uff09
\u5219\u7532\u7684\u5b58\u6d3b\u690d\u682a\u6570\u4e3a\uff1ax\u00d790%
\u4e59\u7684\u5b58\u6d3b\u690d\u682a\u6570\u4e3a\uff1a\uff08500\uff0dx\uff09\u00d795%
\u518d\u8bbe\u7532\u4e59\u5b58\u6d3b\u690d\u682a\u603b\u6570\u4e3a y
\u5219 y\uff1dx\u00d790%\uff0b\uff08500\uff0dx\uff09\u00d795%\uff1d\uff0d0.05x\uff0b475
\u6709\u4e86\u51fd\u6570\uff0c\u518d\u786e\u5b9ax\u7684\u5177\u4f53\u8303\u56f4\u4e4b\u540e\uff0c\u6c42y\u7684\u6700\u5927\u503c\u3002x\u7684\u5177\u4f53\u8303\u56f4\u5982\u4f55\u786e\u5b9a\u5462\uff1f
\u6839\u636e\u82b1\u8d3928000\u5143\u53ef\u4ee5\u5217\u4e00\u4e2a\u4e00\u5143\u4e00\u6b21\u4e0d\u7b49\u5f0f\u5982\u4e0b\uff1a
X\u00d750\uff0b\uff08500\uff0dx\uff09\u00d780\u226428000
\u89e3\u5f97\uff1a x\u2265400
\u518d\u4e0ex\u7684\u521d\u6b65\u8303\u56f4\u6c42\u4ea4\u96c6\u5f97\uff1a 400\u2264x\u2264500
\u6839\u636e\u4e00\u5143\u4e00\u6b21\u51fd\u6570\u662f\u5355\u8c03\u9012\u51cf\u7684\uff0c\u6240\u4ee5x\u53d6\u5f97\u6700\u5c0f\u503c\u65f6\uff0cy\u6709\u6700\u5927\u503c
\u5373x=400\u65f6 \u603b\u6210\u6d3b\u690d\u682a\u6700\u9ad8\uff08\u8fd9\u4e2a\u6761\u4ef6\u867d\u7136\u9898\u76ee\u672a\u8bf4\u660e\uff0c\u4f46\u662f\u6839\u636e\u9898\u610f\u5e94\u8be5\u80fd\u627e\u51fa\u5426\u5219\u6b64\u9898\u5c06\u4e0d\u80fd\u8ba1\u7b97\uff09
\u5e0c\u671b\u80fd\u89e3\u51b3\u4f60\u7684\u95ee\u9898
5a+8（n-a）=2600 a=（8n-2600）/3
0.9a+0.95（n-a）≥0.92n 3n≥5a。
将1式代入2式：
3n≥5（8n-2600）/3
9n≥40n-13000
13000≥31n
419.35≥n
n最大419。
买甲树a乙树b
a+b=n
50a+80b=26000
（0.9a+0.95b）/n>=0.92
n<=507.8
n最大值507
绛旓細璁璐拱鐢x妫碉紝涔檔-x妫.50x+80(n-x)鈮26000 x鈮(8n-2600)/3 (1)0.9x+0.95(n-x)鈮0.92n 3n鈮5x (2)灏(1)寮忎唬鍏(2)寮忥細3n鈮5x鈮5(8n-2600)/3 9n鈮40n-13000 31n鈮13000 n鈮419.35 鎵浠ワ細n鏈澶ф槸419妫碉紝涓嶆槸418妫点
绛旓細涔扮敳鏍a涔欐爲b a+b=n 50a+80b=26000 锛0.9a+0.95b锛/n>=0.92 n<=507.8 n鏈澶у507
绛旓細璁璐拱鐢瞐妫碉紝涔檔-a妫点5a+8锛坣-a锛=2600 a=锛8n-2600锛/3 0.9a+0.95锛坣-a锛夆墺0.92n 3n鈮5a銆傚皢1寮忎唬鍏2寮忥細3n鈮5锛8n-2600锛/3 9n鈮40n-13000 13000鈮31n 419.35鈮 n鏈澶419銆
绛旓細鈶犳牴鎹俊鎭～琛紙鐢ㄥ惈x浠ｆ暟寮忚〃绀猴級锛堟瘡绌烘牸2鍒嗭級 鏍戣嫍绫诲瀷 鐢茬鏍戣嫍 涔欑鏍戣嫍 涔版爲鑻鏁伴噺锛堝崟浣嶏細妫碉級 500-x 涔版爲鑻楃殑鎬昏垂鐢紙鍗曚綅锛氬厓锛 50x 80锛500-x锛 鈶50x+80锛500-x锛=25600锛岃В寰梮=480锛500-x=20锛庣瓟锛氱敳绉鏍戣嫍涔浜480妫碉紝涔绉嶆爲鑻椾拱浜20妫碉紟锛2锛90%x...
绛旓細澶у鐢熷惈娉杩
绛旓細50X+80y<=26000 ,,90%X+95%Y>=92%(x+y),x>0,y>0 n=x+y .. 瑙ｅ緱锛歺=153,y=102,,
绛旓細瑙ｏ細璁璁″垝璐拱鐢绉嶆爲鑻梮鏍锛屼箼绉峺鏍紱锛1锛夌敱棰樺緱 鈶爔+y=6000 鈶5x+8y=36000 瑙ｅ緱x=4000锛寉=2000 锛2锛夌敱棰樺緱 鈶爔+y=6000 鈶5x+8y<=42000 瑙ｅ緱y<=4000.鈭翠箼绉鏍戣嫍璐拱鏁板簲涓嶈秴杩4000 锛3锛夎嫢瑕佷娇杩欐壒鏍戣嫍鐨勬垚娲荤巼涓嶄綆浜93%锛屽嵆瀛樻椿鐨勬牚鏁颁笉浣庝簬6000*93%=5580锛堟牚锛夌敱棰...
绛旓細1銆佽涔扮敳绉鏍戣嫍n鏍紝鏍规嵁棰樻剰寰楁柟绋嬶細24n +(800锛峮)脳30=21000 瑙ｅ緱锛歯=500 涔欑鏍戣嫍涓猴細800锛500=300锛堟牚锛 2銆佽鐢茬鏍戣嫍鏈澶涔皀鏍紝鏍规嵁棰樻剰寰楁柟绋嬶細n脳85% +(800锛峮锛壝90%=800脳88% 瑙ｅ緱锛歯=320 3銆佺敳绉鏍戣嫍涔320鏍锛屼箼绉嶆爲鑻椾拱800锛320=480锛堟牚锛夛紝璐圭敤鏈浣庛 鏈浣...
绛旓細璁鐢蹭拱鏍戣嫍X妫碉紝鍒涔欎拱鏍戣嫍锛500-X锛夋５锛屼緷棰樻剰寰楋紝50X+80锛500-X锛=28000
绛旓細绛旀锛1璁剧敳銆涔欎袱绉嶆爲鑻鍚勪拱浜唜鏍,y鐝狅紝鍒 x+y=800 24x+30y=21000 X=500,y=300 绛 鐢层佷箼涓ょ鏍戣嫍鍚勪拱浜500鏍紝300鏍 2璁剧敳绉嶆爲绉嶄簡x妫碉紝涔绉嶆爲绉嶄簡y妫 85%*x+90%y=800*88 x+y=800 瑙ｅ緱x= 160 锛寉=640 灏辨槸璇磋浣胯繖鎵规爲鑻楃殑鎬绘垚娲荤巼涓嶄綆浜88%鍒鐢叉爲鑻鑷冲璐拱160鏍 3 ...
