如题所述
计ç®ï¼-9÷27/4Ã(-7)+4-4Ã(+4/3)
解ï¼åå¼= 9Ã4/27Ã7+4-4Ã4/3
=4/3Ã7-4Ã4/3+4
=(7-4)Ã4/3+4
=4+4
=8
22/7Ã(22/7-22/3)Ã7/22÷22/21
解ï¼åå¼=22/7Ã(22/7-22/3)Ã7/22Ã21/22
=22/7Ã7/22Ã(22/7-22/3)Ã21/22
=22/7Ã21/22-22/3Ã21/22
=3-7
=-4
(-1)^2011÷1/15+(-1/5)Ã(-5)^3
解ï¼åå¼=(-1)÷1/15+(-1/5)Ã(-125)
=(-1)Ã15+1/5Ã125
= -15+25
=10
-12^56Ã[(-1)^1999-22/3Ã(9/22-6/11)]
解ï¼åå¼=-12^56Ã[(-1)^1999-(22/3Ã9/22-22/3Ã6/11)]
=-12^56Ã[(-1)^1999-(3-4)]
=-12^56Ã(-1+1)
=0
1ã3ab-5ab2+3a2b-4ab+2ab2-3ab
解ï¼åå¼=(3ab-3ab)-4ab+(-5ab2+2ab2)+3a2b
=-4ab+(-5+2)ab2+3a2b
=-4ab+(-3)ab2+3a2b
=-4ab-3ab2+3a2b
2ã2(2x-y)-3(2x-y)2+2x-y-5(2x-y)2
解ï¼åå¼=2(2x-y)-3(2x-y)2+(2x-y)-5(2x-y)2
=[2(2x-y)+(2x-y)]+[-3(2x-y)2-5(2x-y)2]
=(2+1)(2x-y)+(-3-5)(2x-y)2
=3(2x-y)-8(2x-y)2
1ãåç®
(1) (2a+b)-(a-2b)
解ï¼åå¼=2a+b-a+2b
=2a-a+b+2b
=(2-1)a+(1+2)b
=a+3b
(2) -3(a-2b)-2(2a-b)
解ï¼åå¼=-3a+(-3)(-2b)+(-2)(2a)+(-2)(-b)
=-3a+6b-4a+2b
=(-3-4)a+(6+2)b
=-7a+8b
(3) -1/4(-4a+4b/3)-1/3(3a-2b)
解ï¼åå¼=-[1/4•(-4a)+1/4•4b/3]-(1/3•3a-1/3•2b)
=-(-a+b/3)-(a-2b/3)
=a-b/3-a+2b/3
=(a-a)+(-1/3+2/3)b
=b/3
(4) 3x2y-2[3x2y-3(3xyz+2x2z)+x2z]-3xyz
解ï¼åå¼=3x2y-2[3x2y-(9xyz+6x2z)+x2z]-3xyz
=3x2y-2(3x2y-9xyz-6x2z+x2z)-3xyz
=3x2y-2[3x2y-9xyz+(-6x2z+x2z)]-3xyz
=3x2y-2(3x2y-9xyz-5x2z)-3xyz
=3x2y-(6x2y-18xyz-10x2z)-3xyz
=3x2y-6x2y+18xyz+10x2z-3xyz
=-3 x2y+15xyz+10x2z
2ãè¥A=3x2y+4xy2ï¼B=2xy2-x2yï¼æ±-2A-3B
解ï¼-2A-3B=-2(3x2y+4xy2)-3(2xy2-x2y)
=-(6x2y+8xy2)-(6xy2-3x2y)
=-6x2y-8xy2-6xy2+3x2y
=(-6x2y+3x2y)+(-8xy2-6xy2)
=-3x2y-14xy2
3ãå åç®åæ±å¼ï¼è¥ï½x+1ï½+(y-1/3)2=0ï¼æ±8xy-2{xy+3[3x4y-2(x4y+2xy)+5xy]-2x4y}çå¼
解ï¼åç®ï¼åå¼=8xy-2{xy+3[3x4y-(2x4y+4xy)+5xy]-2x4y}
=8xy-2[xy+3(3x4y-2x4y-4xy+5xy)-2x4y]
=8xy-2[xy+3(x4y+xy)-2x4y]
=8xy-2(xy+3x4y+3xy-2x4y)
=8xy-2(4xy+x4y)
=8xy-8xy-2x4y
=-2x4y
ç±ï½x+1ï½+(y-1/3)2=0ï¼å¾
x=-1ï¼y=1/3
å°x=-1ï¼y=1/3ä»£å ¥-2x4yï¼å¾
-2Ã(-1)4Ã1/3=-2/3
æ以ï¼åå¼=-2/3
4ãæä¸éé¢ï¼æ±ä¸¤ä¸ªå¤é¡¹å¼çå·®ãå°åéæ2a2b-3ab2å½ä½è¢«åæ°ï¼è§£å¾å·®ä¸º-a2bï¼æ±æ£ç¡®çå·®ã
解ï¼è®¾A=2a2b-3ab2ï¼C=-a2bï¼å¦å¤ä¸ä¸ªå¤é¡¹å¼ä¸ºB
å°ååçå¼å为ï¼A-B=Cï¼æ以B=A-C
B=(2a2b-3ab2)-(-a2b)
=2a2b-3ab2+a2b
=3a2b-3ab2
æ£ç¡®çå·®åºä¸ºï¼
B-A=(3a2b-3ab2)-(2a2b-3ab2)
=3a2b-3ab2-2a2b+3ab2
= a2b
(å«è§£ï¼å 为a-bä¸b-aæ¯ç¸åæ°ï¼å°åå°è¢«åæ°ååæ°æåäºï¼æ以å¾å°çå·®æ¯æ£ç¡®çå·®çç¸åæ°ï¼å æ¤ï¼æ£ç¡®ç差为-(-a2b)= a2b)
解ï¼åå¼= 9Ã4/27Ã7+4-4Ã4/3
=4/3Ã7-4Ã4/3+4
=(7-4)Ã4/3+4
=4+4
=8
22/7Ã(22/7-22/3)Ã7/22÷22/21
解ï¼åå¼=22/7Ã(22/7-22/3)Ã7/22Ã21/22
=22/7Ã7/22Ã(22/7-22/3)Ã21/22
=22/7Ã21/22-22/3Ã21/22
=3-7
=-4
(-1)^2011÷1/15+(-1/5)Ã(-5)^3
解ï¼åå¼=(-1)÷1/15+(-1/5)Ã(-125)
=(-1)Ã15+1/5Ã125
= -15+25
=10
-12^56Ã[(-1)^1999-22/3Ã(9/22-6/11)]
解ï¼åå¼=-12^56Ã[(-1)^1999-(22/3Ã9/22-22/3Ã6/11)]
=-12^56Ã[(-1)^1999-(3-4)]
=-12^56Ã(-1+1)
=0
1ã3ab-5ab2+3a2b-4ab+2ab2-3ab
解ï¼åå¼=(3ab-3ab)-4ab+(-5ab2+2ab2)+3a2b
=-4ab+(-5+2)ab2+3a2b
=-4ab+(-3)ab2+3a2b
=-4ab-3ab2+3a2b
2ã2(2x-y)-3(2x-y)2+2x-y-5(2x-y)2
解ï¼åå¼=2(2x-y)-3(2x-y)2+(2x-y)-5(2x-y)2
=[2(2x-y)+(2x-y)]+[-3(2x-y)2-5(2x-y)2]
=(2+1)(2x-y)+(-3-5)(2x-y)2
=3(2x-y)-8(2x-y)2
1ãåç®
(1) (2a+b)-(a-2b)
解ï¼åå¼=2a+b-a+2b
=2a-a+b+2b
=(2-1)a+(1+2)b
=a+3b
(2) -3(a-2b)-2(2a-b)
解ï¼åå¼=-3a+(-3)(-2b)+(-2)(2a)+(-2)(-b)
=-3a+6b-4a+2b
=(-3-4)a+(6+2)b
=-7a+8b
(3) -1/4(-4a+4b/3)-1/3(3a-2b)
解ï¼åå¼=-[1/4•(-4a)+1/4•4b/3]-(1/3•3a-1/3•2b)
=-(-a+b/3)-(a-2b/3)
=a-b/3-a+2b/3
=(a-a)+(-1/3+2/3)b
=b/3
(4) 3x2y-2[3x2y-3(3xyz+2x2z)+x2z]-3xyz
解ï¼åå¼=3x2y-2[3x2y-(9xyz+6x2z)+x2z]-3xyz
=3x2y-2(3x2y-9xyz-6x2z+x2z)-3xyz
=3x2y-2[3x2y-9xyz+(-6x2z+x2z)]-3xyz
=3x2y-2(3x2y-9xyz-5x2z)-3xyz
=3x2y-(6x2y-18xyz-10x2z)-3xyz
=3x2y-6x2y+18xyz+10x2z-3xyz
=-3 x2y+15xyz+10x2z
2ãè¥A=3x2y+4xy2ï¼B=2xy2-x2yï¼æ±-2A-3B
解ï¼-2A-3B=-2(3x2y+4xy2)-3(2xy2-x2y)
=-(6x2y+8xy2)-(6xy2-3x2y)
=-6x2y-8xy2-6xy2+3x2y
=(-6x2y+3x2y)+(-8xy2-6xy2)
=-3x2y-14xy2
3ãå åç®åæ±å¼ï¼è¥ï½x+1ï½+(y-1/3)2=0ï¼æ±8xy-2{xy+3[3x4y-2(x4y+2xy)+5xy]-2x4y}çå¼
解ï¼åç®ï¼åå¼=8xy-2{xy+3[3x4y-(2x4y+4xy)+5xy]-2x4y}
=8xy-2[xy+3(3x4y-2x4y-4xy+5xy)-2x4y]
=8xy-2[xy+3(x4y+xy)-2x4y]
=8xy-2(xy+3x4y+3xy-2x4y)
=8xy-2(4xy+x4y)
=8xy-8xy-2x4y
=-2x4y
ç±ï½x+1ï½+(y-1/3)2=0ï¼å¾
x=-1ï¼y=1/3
å°x=-1ï¼y=1/3ä»£å ¥-2x4yï¼å¾
-2Ã(-1)4Ã1/3=-2/3
æ以ï¼åå¼=-2/3
4ãæä¸éé¢ï¼æ±ä¸¤ä¸ªå¤é¡¹å¼çå·®ãå°åéæ2a2b-3ab2å½ä½è¢«åæ°ï¼è§£å¾å·®ä¸º-a2bï¼æ±æ£ç¡®çå·®ã
解ï¼è®¾A=2a2b-3ab2ï¼C=-a2bï¼å¦å¤ä¸ä¸ªå¤é¡¹å¼ä¸ºB
å°ååçå¼å为ï¼A-B=Cï¼æ以B=A-C
B=(2a2b-3ab2)-(-a2b)
=2a2b-3ab2+a2b
=3a2b-3ab2
æ£ç¡®çå·®åºä¸ºï¼
B-A=(3a2b-3ab2)-(2a2b-3ab2)
=3a2b-3ab2-2a2b+3ab2
= a2b
(å«è§£ï¼å 为a-bä¸b-aæ¯ç¸åæ°ï¼å°åå°è¢«åæ°ååæ°æåäºï¼æ以å¾å°çå·®æ¯æ£ç¡®çå·®çç¸åæ°ï¼å æ¤ï¼æ£ç¡®ç差为-(-a2b)= a2b)
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第1个回答 2012-01-19
1.解不等式(1)x/3-x/2<1 (2)-3x<x+4
2.解不等式组(1){x-1>0 x-5>0 -x+6<0
(2){2x-1>0 3x+1<0
(3){-1/2*x<1 x-3<0 2x<1
3.计算(1)-9÷27/4×(-7)+4-4×(+4/3) (2)(-1)^2011÷1/15+(-1/5)×(-5)^3
4.化简(1) -3(a-2b)-2(2a-b) (2)3x²y-2[3x²y-3(3xyz+2x²z)+x²z]-3xyz
答案
1.(1)x>-6(2)x>-1
2.(1)x>6(2)空集(3)-2<x<1/2
3.(1)8(2)10
4.(1)-7a+8b (2)-3 x²y+15xyz+10x²z本回答被提问者和网友采纳
2.解不等式组(1){x-1>0 x-5>0 -x+6<0
(2){2x-1>0 3x+1<0
(3){-1/2*x<1 x-3<0 2x<1
3.计算(1)-9÷27/4×(-7)+4-4×(+4/3) (2)(-1)^2011÷1/15+(-1/5)×(-5)^3
4.化简(1) -3(a-2b)-2(2a-b) (2)3x²y-2[3x²y-3(3xyz+2x²z)+x²z]-3xyz
答案
1.(1)x>-6(2)x>-1
2.(1)x>6(2)空集(3)-2<x<1/2
3.(1)8(2)10
4.(1)-7a+8b (2)-3 x²y+15xyz+10x²z本回答被提问者和网友采纳
第2个回答 2012-01-19
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