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(1)原式=5a+4c+7b+5c3b6a=a+4b+9c. (2)原式=8xyX+yx+y8xy=2x+2y. (3)源式=2x1/2+3x4x+4x2=6Xx5/2. (4)原式=3x(7x4x+32x)=3x7x+4x3+2x=5x3x3. ?。?x+5+4x)+(5x4+2x)=x+5+4x+5x4+2x=x+9x+1. 當x=2時,原式=(2)+9(2)+1=418+1=13. ?。?1)比a的5倍大4的數(shù)為5a+4,比a的2倍小3的數(shù)是2a3. (5a+4)+(2a3)=5a+4+2a3=7a+1. (2)比x的7倍大3的數(shù)為7x+3,比x的6倍小5的數(shù)是6x5. (7x+3)(6x5)=7x+36x+5=x+8. ?。核痉N植面積為3ahm,玉米種植面積為(a5)hm, 3a(a5)=3aa+5=(2a+5)(hm). :(1)πa/2+4a=(π+8)/2a(cm). (2)πa+2a3=πa+6a=(π+6)a(cm). ?。?(a+y)+(ay)=3a+3y+=+. ?。?7a,20a,…,(3n+2)a. ?。篠=3+3(n2)=3n3. 當n=5時,S=353=12; 當n=7時,S=373=18; 當n=11時,S=3113=30. ?。?1)10b+a;(2)10(10b+a);(3)10b+a+10(10b+a)=11(10b+a). 這個和是11的倍數(shù),因為它含有11這個因數(shù). . 單項選擇 翻譯句子 1.—How are you? —I am fine,thanks. 2.—What is this in English? —It is an orange. 3.—What color is the pen? —It is white and black. 4.—Spell“hello”,please. 5.—The quilt is yellow. 詞匯 任務(wù)型閱讀 ,To