数学书，112页，拓广探索10，11题
\u521d\u4e00\u4e0b\u6570\u5b66\u4e66\u7b2c91\u9875\u62d3\u5e7f\u63a2\u7d22\u600e\u4e48\u505a91\u9875
9\u3001
\u89e3\uff1a
\u22201+\u22202+\u22203+\u22204+100\u00b0=180\u00b0
\u56e0\u4e3a\u22201=\u22202\uff0c\u22203=\u22204\uff0c\u6240\u4ee52\u22202+2\u22204=80\u00b0\u5373\u22202+\u22204=40\u00b0
x\u00b0=180\u00b0-\uff08\u22202+\u22204\uff09=140\u00b0\uff0c\u5373x=140\u00b0
10\u3001
\u8bc1\u660e\uff1a
\uff081\uff09\u2235 GB\uff0cCG\u5206\u522b\u5e73\u5206\u2220ABC\u4e0e\u2220ACB\uff0c\u2234\u22201=\u22202\uff0c\u22203=\u22204\uff0c
\u2220BGC=180\u00b0-\u22202-\u22204=180\u00b0-\uff081/2\uff09(\u2220ABC+\u2220ACB)
\uff082\uff09\u2220BGC = 180\u00b0-\uff081/2\uff09(\u2220ABC+\u2220ACB) = 180\u00b0-\uff081/2\uff09(180\u00b0-\u2220A)
=180\u00b0-90\u00b0+\uff081/2\uff09\u2220A = 90\u00b0+\uff081/2\uff09\u2220A
\u80fd\u628a\u9898\u76ee\u7ed9\u6211\u5417
11题 解设上坡下坡平路各是X千米Y千米Z千米 列方程组:X+Y+Z=3.3 X÷3+y÷4+Z÷5=51÷60 X÷5+y÷4+Z÷3=53.4÷60解得X=1.2 y=0.6 Z=1.5好难。。。我飘过。。。
绛旓細11棰 瑙ｈ涓婂潯涓嬪潯骞宠矾鍚勬槸X鍗冪背Y鍗冪背Z鍗冪背 鍒楁柟绋嬬粍:X+Y+Z=3.3 X梅3+y梅4+Z梅5=51梅60 X梅5+y梅4+Z梅3=53.4梅60瑙ｅ緱X=1.2 y=0.6 Z=1.5
绛旓細p119 10.瑙ｈ锛1瑙掓湁x鏋氾紝5瑙掓湁y鏋氾紝1鍏冩湁z鏋氥倄+y+z=15 { x+5y+10z=70 瑙ｅ緱 x=5 { y=7 z=3 11.瑙ｈ锛氫粠鐢插湴鍒颁箼鍦颁笂鍧′负X鍗冪背锛屽钩璺负y鍗冪背锛屼笅鍧′负z鍗冪背銆倄+y+z=3.3 锝 3鍒嗕箣x+4鍒嗕箣y+5鍒嗕箣z=60鍒嗕箣51 5鍒嗕箣x+4鍒嗕箣y+3鍒嗕箣z=60鍒嗕箣53.4 瑙ｅ緱 ...
绛旓細8.2蟺r-2蟺r+2蟺脳浜屽垎涔嬩竴r+2蟺+涓夊垎涔嬩竴r+2蟺+鍏垎涔嬩竴r=0绛斾竴鏍峰9.a+1a+1m=a+n-1褰揳=20鏃秐=19鏃秏=20+19-1=38鎷撳箍鎺㈢储10.10a+b10b+a(10b+a)+(10a+b)=11(a+b)杩欎釜鏁拌兘琚11鏁撮櫎11.锛1锛48-a-锛2a+3)-(a+2a+3)=42-6a(2)涓嶈兘12.锛1锛夛紙4+2-1)(b)=...
绛旓細11.瑙ｏ細璁鹃攢鍞噺瑕佹瘮鎸夊師浠烽攢鍞椂澧炲姞x銆(1 - 20%)(1 + x) = 1 80% + 80%x = 1 80%x = 1 - 80 80%x = 20 x = 20% 梅 80 x = 25 绛旓細閿鍞噺瑕佹瘮鎸夊師浠烽攢鍞椂澧炲姞25%銆12.1锛夎В锛氳浜哄潎瀹氶鏄痻浠躲傦紙4x+20锛/4=锛6x-20锛/5 5锛4x+20锛=4锛6x-20锛20x+100=...
绛旓細9 .瑙ｈ姣忎釜鎴块棿闇瑕佺矇鍒风殑澧欓潰闈㈢Н涓簒 m²,鏍规嵁棰樻剰寰8x-50/3-10x+40/5=10 x=5210.瑙ｈA b涓ゅ湴鐨勮矾绋嬩负xkm,鏍规嵁棰樻剰x+36=36x2x2 x=10811.x闄102. 300鍔燲闄203.涓嶄細鍙4.X闄10绛変簬300鍔2X闄20X绛変簬300 鏈洖绛旂敱鎻愰棶鑰呮帹鑽 涓炬姤| 璇勮 73 21 ...
绛旓細8.2蟺r-2蟺r+2蟺脳浜屽垎涔嬩竴r+2蟺+涓夊垎涔嬩竴r+2蟺+鍏垎涔嬩竴r=0 绛 涓鏍峰 9.a+1 a+1 m=a+n-1 褰揳=20鏃 n=19鏃 m=20+19-1=38 鎷撳箍鎺㈢储 10.10a+b 10b+a (10b+a)+(10a+b)=11(a+b)杩欎釜鏁拌兘琚11鏁撮櫎 11.锛1锛48-a-锛2a+3)-(a+2a+3)=42-6a (2) 涓嶈兘 ...
绛旓細12.瑙ｏ細璁剧鐢叉湁x鍙緤锛屽垯鐗х涔欐湁锛坸-2锛夊彧 X+1=2(X-2-10)x=7 寰梮-2=5 绛旓細鐗х鐢叉湁7鍙緤锛岀墽绔ヤ箼鏈5鍙緤.13.瑙ｏ細璁炬煇鍟嗗搧鍘熶环涓篴鍏冿紝鍒欓檷浠峰悗涓猴紙1-10%锛塧鍏冿紝鍘熼攢鍞噺涓篵涓紝璁鹃檷浠峰悗閿鍞噺涓簒涓 ab=锛1-10%锛塧*x x=锛10/9锛塨 [锛10/9锛塨-b]/b绾=11.1 绛...
绛旓細瑙ｏ細璁鹃粍閲戜綋绉负x绔嬫柟鍘樼背銆19.3x/a*100%>=90 鎵浠ラ粍閲戠殑浣撶Н搴旀弧瓒 19.3x/a>=0.9
绛旓細浣犲彂涓鐩紝鎴戞墠鑳藉府浣
绛旓細91椤 9銆佽В锛氣垹1+鈭2+鈭3+鈭4+100掳=180掳 鍥犱负鈭1=鈭2锛屸垹3=鈭4锛屾墍浠2鈭2+2鈭4=80掳鍗斥垹2+鈭4=40掳 x掳=180掳-锛堚垹2+鈭4锛=140掳锛屽嵆x=140掳 10銆佽瘉鏄庯細锛1锛夆埖 GB锛孋G鍒嗗埆骞冲垎鈭燗BC涓庘垹ACB锛屸埓鈭1=鈭2锛屸垹3=鈭4锛屸垹BGC=180掳-鈭2-鈭4=180掳-锛1/2锛(鈭燗BC+...
