复杂方程计算专项练习题.

1、小学复杂方程专项练习题(6) X+ (3X- 16)匚=10 (X+1),4(1) 2x+5=5x - 7,(7)x+仁 x+3,2 2(2) 3 (x- 2) =2 - 5 (x - 2),(8) 6 (3x - 2)- 4 ( 4x- 3) =1 - 8x,(3)- =146，(9) 4 (x - 2) +20x - 4=5 (1 - 2x),(4)5 - (X+16.81 )=,5(10) 1.6 - (x - 0.45 ) =5,0.2x+ 厶=8-5(16) 2 (x+2) 3=3x 5,(12) x15+0.4=x 12 - 0.1 ,(17) x+ (3x 16)吃5%=10(

2、x+1),(13)150.5 (18)丄 x 1.4=3.6+ x,43( 11) 35 (x 2) 15 ( 5x 6) = ( 22x 63) 21 ( 3x 4),(19) 1.2 :-43 5(14)x 2 =0.25 x,71123(15) 5X+7.25-12 2.5X ,4(20)2x-=8+x,(21) 8 (x - 2) =2x+7.(26) (X+12) X=42 - X,5(22) 6(x- 3.5 ) =17.8+2x ,(27) 2 - (X 0 55)=三77(23) 5 -(x+16.84 ) =0.2 ,(28) 7X( x+6) - 3x=4 X( 2x+5)

3、,(29)=2.5 ,3x+5(30)60 -(x+10) =5(24) ( 9+X) : (9 - X) =5 : 3,(25) x+ (3x - 16)吃5%=10( x+2),(37) 3 (x+2) =4 (x+1),(31) ； (28 - 2x) =6 (x - 5)s(32)64 -( 2x- 5) =32(38) 丄(x+2) =x+14(34) 1 - (x - 45% =2.8 ,5(39) 76 (x- 2) =52x - 32(35) 5 (X+4) =26.6 - X,(40) 81x - 342=76 (x - 2)(36) 100X0.5+ (x- 100) (4

4、1) 3 (2 - x) +5 (4x- 3) =4 (x+1)(42) 15-( 5.5 - x) =2x(47) 30%x+85=70%x+25(43) 16+x=12+2x+x(48)8.5 X1.2 - 5.3x=8.5 - 4x(44) 2 ( x- 4) =3 (x - 12)(49)5x - 2 ( 3 - 2x) =16x- 23(45) 0.4 + (4 - x) =1 詔(50)(x - 5) X5 - 9= (x- 12) X12(46) 8 ( x- 2) =2 (x+7),(51)(10 - x)吃=5x - 7(53) 8- 5 (6x+0.7 ) =10x+0.5

5、 ,(58)(54) 8.5x - 3.9x=55.2( x- 18),(59)(55) 122 - x- 19= (x - 19) X5,(60)(56) 3.5x+2=4x - 1,(61): = 3 5 1. 5X+ (3X- 16)吃5%=10( X+1)75 - (x+10) =2,5x - 3X (28 - x) =12+2x,6 (x+1) =0.5 ( 10x+16),(63) 127.5 -( 2x+3) =15,(68) 2.8x=19.32 - 6.4x ,(64) 3 (x+2) =4 (x+1),(69) 5 (y - 4)- 7 ( 7- y)- 9=12 - 3

6、(9 - y),(65) 8 (x- 1.5 ) =x+0.6 ,(70) 35 (x - 2) - 15 (5x - 6) =22x - 63 - 21 ( 3x- 4),(66) 7 ( x+6)- 3x=4 (2x+5),(71) 2.6x=51.6 - 3.4x ,(73) 20+4x=6x - 24,(78) 35 (2- x) +15 (6- 5x) =22x+7+21 ( 4- 3x),(74) 5 ( x- 1) =x+1,(79) 5 ( 3x - 4)- 2 (x - 1) =5( 2x- 1)(75) 3 ( 3x- 2) =10- 0.5 (x - 3.5 ),(80)

7、：+ x,35(76) 0.4 (x- 0.2 ) +1.5=0.7x - 0.38 ,(81) 3x+5 X =2x+ x：44 3(83) 4 ( 4x- 6) =5 (3x+1),(88) x- 2.5= (x- 1.8 ) X2(84) 10X=3 (2X+17) +45,(89) 12+ (x - 12) X + x=x5 2(85) 5.7 (X- 0.2 ) =5.1 (X+0.6 ) +4,(90) 3 (X- 3) +4 ( 3X- 2) =7 (2 - X),(86) (3x+4) +x=7 (x - 5)(91)3X-22X+3 _3X+2- = 小学复杂方程专91题参考

8、答案:(1) 2x+5=5x - 7,2x+5 - 2x=5x - 7 - 2x,3x - 7=5,3x - 7+7=5+7,3x=12,3x -3=123,x=4;(2) 3 (x- 2) =2 - 5 (x - 2),3x- 6=12 - 5x,3x - 6+5x=12 - 5x+5x ,8x- 6=12,8x - 6+6=12+6 ,8x=18,8x=18 J,x=2.25;0.2x+- x=8- - x+ _Lx, 5丄5丄5丄541.8x+-=8 ,51.8x+ 丄=8丄5 551.8x=7.2,1.8x.8=7.2 1.8 ,x=4(6) X+ (3X- 16) =10 ( X+1

9、),4X+ ( 3X- 16) X4=10X+10 ,X+12X- 64=10X+10 ,13X- 64=10X+10 ,13X- 64+64=10X+10+64 ,13X=10X+74,v+2 2y - 3(3)-=1 ,46(-)怎4=1怎4,466 (y+2)- 4 ( 2y - 3) =24 ,30- 2y=24,-2y+2y=24+2y ,3013X- 10X=10X+74 - 10X ,3X=74,3X=74 3 ,X=74J(7)x+1= -x+3 ,2 2311ix+1 - x= x+3 - x ,22 222y+24=302y+242y=62y-24=30 - 24,吃=6T

10、,x+1=3,x+1 1=3 - 1,x=2(8) 6 ( 3x 2) 4 (4x 3) =1 8x,18x 1218x-10x=1x=1x=16x+12=1 8x,16x+8x=0,0,1IH；y=3(4)5 (X+16.81 )=丄55 (X+16.81 ) X (X+16.81 ) =一 X (X+16.81 ),5-X (X+16.81 ) =5,5-X (X+16.81 ) X5=5X5,5X+16.81=25,X+16.81- 16.81=25 - 16.81 ,(9) 4 ( x 2) +20x 4=5 ( 1 2x), 4x 8+20x 4=5 10x , 24x+10x=5+

11、12,34x=17,x=1734 ,10.2x+=8 -5(5)(10) 1.6 (x 0.45 ) =5 ,x- 0.45=1.6 5,x- 0.45=0.32 ,x=0.32+0.45,x=0.77;(11) 35 (x- 2)- 15 ( 5x- 6) = (22x - 63)- 21 (3x - 4),35x- 70- 75x+90=22x - 63 - 63x+84,35x- 70 - 75x+90-22x+63x=22x -63-63x+84-22x+63xx+20=21,X+20-20 =21- 20,x=1(12) x詔 5+0.4=x -12 - 0.1 ,x+0.4=x-

12、0.1 ,1512x+0.4 -x=x - 0.1 -x,1515 12150.4+0.仁x - 0.1+0.1 ,600.560x60,60x=307.5X=5,7.5X.5=5 -7.5 ,X=：.3(16) 2 (x+2)- 3=3x - 5,2x+4- 3=3x - 5 ,2x+1+5=3x- 5+5 ,2x+6=3x,2x+6- 2x=3x - 2x ,x=6.(17) x+ ( 3x - 16) 勺5%=10( x+1),x+12x13x13x3x3xx=-64=10x+10,-64=10x+10,-64 - 10x=10x+10 - 10x ,-64+64=10+64,-3=74

13、-3 ,(18)-lx - 1.4=3.6+ 上x,43：x - 1.4 -】x=3.6+ ：x - ：x ,4333(13) 150.5- 150.5- 150.5- 3.5x=7 ,150.5- 3.5x+3.5x=7+3.5x,150.5 - 7=7+3.5x - 7,143.5 -3.5=3.5x -3.5 , x=414R1(14) -x - 2=0.25 - x ,71123x - 2丄+, =0.25 -x+-711 2823 2317 o 5 nx - 2=0.25 ,28 11x - 2+2=0.25+22311 1111X ：=2； ：,2S 17 44 17x=411(1

14、5) 5X+7.25=12 - 2.5X ,4，5X+7.25+2.5X=12 - 2.5X+2.5X ,4一x - 1.4=3.6 ,12x - 12-x=5 ,121.1 仁.1x=512 12 12x=60,(19) 1.2 :=,3 59 x=1.2 X5 ,3x=6x=97.5X+7.25=12-47.5X+7.25- 7.25=12- 7.25 ,4疋+ ?(20).=8+x ,(. J 3= ( 8+x )X3 ,5x- 2=24+3x,5x - 2 - 3x=24+3x - 3x ,2x- 2=24 ,2x - 2+2=24+2,2x=26,2x吃=26勺,x=13(21) 8

15、 (x 2) =2x+7 ,8x 16+16=2x+7+16,8x=2x+23,8x- 2x=2x+23 - 2x,6x=23,6x弋=23W,x=3二6(22) 6(x 3.5 ) =17.8+2x ,6x 21=17.8+2x ,6x 21 2x=17.8+2x 2x ,4x 21+21 = 17.8+21 ,4x泊=38.8 詔,x=9.7;(23) 5- (x+16.84 ) =0.2 ,5- (x+16.84 ) X (x+16.84 ) =0.2 X (x+16.84 ), 5=0.2x+3.368,5 3.368=0.2x+3.368 3.368 ,1.632P.2=0.2x P

16、.2 ,x=8.16;(24) ( 9+X) : ( 9 X) =5: 3 ,3( 9+X) =5 ( 9 X),3X9+3X=5X9 5X ,27+3X=455X ,3X+5X=45 27 ,8X=18,8X为=18% ,_X+ l=42 X,552x+型-廻=42 X -聖,5555：x=2 X5 ，X+XX=15 W亠XX=X ,57X=(27) 2-7(X 0 55)=:72 - +(X 0 55) X (X 70.55 ) = X (X7X (X- 0.55 ) = ,77X-0.55 )X =,0.55=,320.55 ),(25)x+ (3x 16)吃5%=10 (x+2),x+

17、(3x 16)-=10x+10 X2 ,4x+(3x -16)X4=10x+20 ,x+3xX4 16X4=10x+20 ,x+12x 64=10x+20,x+12x 10x=20+64 ,3x=84,3x-K3=843 ,x=282( 26) (X+12) X =42 X,529X+12X =42 X ,55(28) 7 X(x+6) 3x=4 X(2x+5),7x+42 3x=8x+20 ,42+4x=8x+20,4x+20=42,4x+20 20=42 20,4x=22,4x-44=224 ,x=5.5;15(29) =2.5 ,15=2.5 X ( 3x+5),7.5x+12.5=15

18、,7.5x+12.5 12.5=15 12.5 ,7.5x=2.5,7.5x 叼.5=2.5 .5 ,x=3(30) 60- (x+10) =560- (x+10) X (x+10) =5(x+10)5x+50=605x+50 50=60 505x=105x-5=105x=2(31) - ( 28 - 2x) =6 (x - 5)8-上x=6x - 3024213+30=6x+二 x2442X x I = X 4 27 2 27x=6(32) 64 - ( 2x - 5) =3264-( 2x - 5) X ( 2x - 5) =32 X ( 2x - 5)64x=160+6464x=2246

19、4x-64=224 代4(33) 81x- 342=76 X (x - 2)81x - 342=76 Xx - 15281x - 76x=342 - 1525x=1905x -5=190 5x=382(34) 1- (x - 45% =2.8 ,51.4 (x - 0.45 ) =2.8 ,x- 0.45=1.4 吃.8 ,x 0.45=0.5 ,x - 0.45+0.45=0.5+0.45,(35) 5 (X+4) =26.6 - X,5x+20+x=26., 6 - x+x,6x+20 - 20=26.6 - 20,6x5=6.6 W,(36) + (x - 100) X0.4x+10-

20、0.4x=0.48x - 0.08x=100.08x).08=10 ).08x=125.(37) 3 (x+2 ) =4 (x+1),3x+6=4x+4,3x+6 - 3x=4x+4 - 3x,x+4=6,x+4 4=6 - 4 ,x=2(38) (x+2) =x+14_x+_=x+14 2_x+_ _ _ =x+1 -4 2 22Jx=x - 142二 X -二 x=x -丄-二 x442 4-x - + =0+42 22x=4 22x X4= X442x=2(39) 76 (x - 2) =52x - 3276x- 152=52x - 3276x - 152+152=52x - 32+15

21、276x=52x+12076x- 52x=52x+120 - 52x24x=12024x4=120 煜4x=5.(40) 81x - 342=76 ( x- 2)81x- 342=76x - 152 ,81x 342+342=76x 152+342 ,81x=76x+19081x- 76x=76x+190 - 76x5x=1905xj=190 jx=38(41) 3 ( 2 - x) +5 ( 4x - 3) =4 ( x+1)6- 3x+20x - 15=4x+417x- 9=4x+417x- 4x+9 - 9=4x - 4x+4+913x=1313x3=13 3x=1(42) 15 -(

22、5.5 x) =2x15- 5.5+x=2x2x 7x=177x=17-7(43) 16+x=12+2x+x16+x=12+3x3x x=16 122x=4x 勺=4吃x=2(44) 2 (x 4) =3 (x 12)2x 8=3x 362x 8 2x=3x 2x 368=x 368+36=x 36+36x=28x=177(50) (x 5) X5 9= ( x 12) X125x 25 9=12x 1445x 34=12x 1445x 34 5x+144=12x 144 5x+1447x=1107x-7=110 x=17(51) (10 x)煜=5x 710 x=10x 1410 x+x+1

23、4=10x 14+x+14(45) 0.4 - ( 4 x) =1 刊=1(4-x)41.6=4 x1.6+x=4 x+x1.6+x=41.6+x 1.6=4 (46) 8 (x 2) =2 (x+7),8x 16=2x+14,8x 16 2x=2x+14 2x,6x 16+16=14+16 ,6x-6=30 -6,x=5(47) 30%x+85=70%x+250.3x+85 0.3x=0.7x+25 0.3x ,0.4x+25=85,0.4x+25 25=85 25,0.4x=60,0.4x-).4=60 -).4 ,x=150(48) 8.5 X1.2 5.3x=8.5 4x10.2 5.

24、3x=8.5 4x10.2 5.3x+5.3x 8.5=8.5 4x+5.3x 11x=2411x-1=24 12411(52) 2.7x 1.8=1.2x+2.7,2.7x 1.8+1.8=1.2x+2.7+1.8,2.7x 1.2x=1.2x+4.5 1.2x ,1.5x-.5=4.5 -.5 ,x=3(53) 8 5 (6x+0.7 ) =10x+0.5 ,8 30x 3.5=10x+0.5 ,4.5 30x+30x=10x+0.5+30x ,4.5 0.5=40x 0.5 ,4-10=40x -40,x=0.1;(54) 8.5x 3.9x=55.2(x 18),4.6x=55.2x

25、993.6 ,4.6x 4.6x=55.2x 993.6 4.6x ,50.6x 993.6=0 ,50.6x 993.6+993.6=993.6,50.6x=993.6,50.6x-50.6=993.6 -50.6 ,x=19.x=-.3=1.7 -.3n(49) 5x 2 ( 3 2x) =16x 235x 6+4x=16x 239x 6=16x 239x 6 9x+23=16x 23 9x+23(55) 122 x 19= ( x 19) X5 ,103 x=5x 95,103 x+x=5x 95+x ,103+95=6x 95+95 ,198-5=6x -6 ,x=33;(56) 3.

26、5x+2=4x - 1 ,3.5x+2 - 3.5x=4x - 1 - 3.5x ,2+1=0.5x- 1 + 1,3弋.5=0.5x 弋.5 ,x=65x+10=4x+36,5x 4x=36 10, x=26(57)4 - 164=10X+1013X 64=10X+1013X 64+64=10X+10+6413X=10X+7413X 10X=10X+74 10X3X=74X=74( 59)75 - (x+10) =2,75-(x+10) X (x+10)=2X (x+10),2x+20=752x+2020=75 20,2x=552x( 60) 5x 3X (28 x) =12+2x,8x 8

27、4=12+2x,8x 84+84=12+2x+84 ,8x=96+2x,8x 2x=96+2x 2x,6x=96,6x代=96弋，x=16(61) 6 (x+1 ) =0.5 (10x+16 ),6x+6=5x+8,6x+6 6=5x+8 6,6x 5x=5x+2 5x,x=2(63) 127.5 - (2x+3) =15,127.5 -( 2x+3) X ( 2x+3) =15X ( 2x+3),15X ( 2x+3) =127.5 ,15 X ( 2x+3) 5=127.5 -15,2x+3=8.5,2x+3 3=8.5 3,2x=5.5,2x吃=5.5 吃,x=2.75;(64) 3 (

28、x+2) =4 (x+1 ),3x+6=4x+4,3x+6 3x=4x+4 3x ,x+4=6,x+4 4=6 4 ,x=2;(65) 8 (x 1.5 ) =x+0.6 ,8x 12=x+0.6 ,8x 12+12=x+0.6+12 ,8x=x+12.6,8x x=x+12.6 x ,7x=12.6,7x =12.6 7 , x=1.8;(66) 7 (x+6) 3x=4 ( 2x+5),7x+42 3x=8x+20 ,4x+42=8x+20,4x+42 4x=8x+20 4x ,4x+20=42,4x+20 20=42 20,4x=22,4x-44=224 ,x=5.5;(67) 4x 2

29、 ( 5.5 x) =3.5x 8 ,4x 11+2x=3.5x 8 ,6x 11=3.5x 8 ,6x 11 + 11=3.5x 8+11 ,3.5x+3=6x,3.5x+3 3.5x=6x 3.5x ,2.5x=35x13x3x(68) 2.8x=19.32 - 6.4x ,2.8x+6.4x=19.32- 6.4x+6.4x ,9.2x=19.32,9.2x-9.2=19.32 兀.2 ,x=2.1;(69) 5 (y - 4)- 7 (7 - y)- 9=12 - 3 ( 9 - y),5y- 20 - 49+7y - 9=12 - 27+3y ,12y- 78=3y - 15,12y

30、- 78+78=3y - 15+78,12y- 3y=3y+63 - 3y ,9y=63,9y用=63乜，y=7(70) 35 (x- 2)- 15 ( 5x - 6) =22x - 63 - 21 ( 3x - 4),35x- 70 - 75x+90=22x - 63 - 63x+84 ,35x- 75x - 22x+63x= - 63+84 - 90+70,x=1(71) 2.6x=51.6 - 3.4x ,2.6x+3.4x=51.6- 3.4x+3.4x ,6x=51.6,6x-6=51.6 W,(72) 3 (4x - 2)- 2 ( 3x+3) =9 - 8x ,6x 12=9 8

31、x,6x 12+8x=9 8x+8x,14x 12=9,14x 12+12=9+12,14x=21,14x-14=21 4,x=1.5;(73) 20+4x=6x 24,20+4x 4x=6x 24 4x,2x 24=20 ,2x 24+24=20+24,2x=44,2x-=44?,x=22;(74) 5 (x 1) =x+1 ,5x 5=x+1 ,5 x=x+1 x ,4x 5=1,4x 5+5=1+5,4x=6,4x泊=6l ,(75) 3 ( 3x 2) =10 0.5 (x 3.5 ),9x 6=11.75 0.5x ,9x 6+0.5x=11.75 0.5x+0.5x ,9.5x 6

32、=11.75 ,9.5x 6+6=11.75+6 ,9.5x=17.75,9.5x-9.5=17.75 ).5 ,47x=；33(76) 0.4 (x 0.2 ) +1.5=0.7x 0.38 ,0.4x+1.42=0.7x 0.38 ,0.4x+1.42 0.4x=0.7x 0.38 0.4x ,0.3x 0.38=1.42 ,0.3x 0.38+0.38=1.42+0.38,0.3x=1.8,0.3x).3=1.8 ).3 ,x=6(77) ( 0.6x+420 ) (x+20) =3 ,(0.6X+420 ) (x+20 ) X (x+20) =3X( x+20 ),3( x+20) =

33、0.6x+420 ,3x+60=0.6x+420,3x+60 0.6x=0.6x+420 0.6x ,2.4x+60=420,2.4x+60 60=420 60,2.4x=360,2.4x吃.4=360 煜.4 ,x=150(78) 35 (2 x) +15 (6 5x) =22x+7+21 (4 3x),160 110x=91 41x,160 110x+110x=91 41x+110x ,69x+91=160,69x+91 91=160 91,69x=69,69x59=69 59 ,x=1(79) 5 ( 3x 4) 2 (x 1) =5 ( 2x 1)15x 20 2x+2=10x 5 ,13x 18=10x 5 ,18 10x=10x 5 10x ,18= 5,3x=13,3x-3=133,x=I：；3(80)_x=4.9+_x,353 55 515x15 77-x - Jix=4.9+ Jix - - x,(81) 3x+5 X =2x+