复杂方程计算专项练习91题有答案

1、小学复杂方程专项练习91题（有答案）(1) 2x+5=5x - 7,(6) X+ (3X - 16) - =10 (X+1 ),(7)x+ 1=_x+3 ,2 24(2) 3 (x- 2) =2 - 5 ( x- 2),(8) 6 (3x - 2)- 4 ( 4x- 3) =1 - 8x,(4)5- (X+16.81 )=,5(9) 4 (x - 2) +20x - 4=5 ( 1 - 2x),(10) 1.6- (x- 0.45) =5,(16)2 (x+2 ) 3=3x 5,( 11) 35 (x 2) 15 (5x 6) = ( 22x 63) 21 ( 3x 4),(12) x15+0

2、.4=x T2 0.1 ,(17) x+ ( 3x 16)吃5%=10 (x+1 ),(13)150.5 4x=7-0.5x(18)丄 x 1.4=3.6+二 x,43(14)x 2 丄=0.25 x,711 2S(19)1.2:：=3 5(15)5X+7.25=12 二2.5X ,4(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)='：,77(23)5- (x+16.84) =0.2,(28) 7X (x+6 ) - 3x=4 X (2x+5

3、),(24)(9+ X : ( 9 - X =5: 3,(29)=2.5,3x+5(25) x+ (3x - 16)吃5%=10 (x+2 ),(30)60-(x+10 ) =5(37) 3 (x+2 ) =4 (x+1),(31)1 (28 - 2x) =6 (x - 5)s(36) 100 >0.5+ (x - 100) X).4=0.48x(41) 3 (2 - x) +5 (4x - 3) =4 ( x+1)(32)64+( 2x - 5) =32(38) ' (x+2) =x+14(34) 1 + (x - 45%) =2.8,5(39) 76 (x- 2) =52x

4、- 32(35) 5 (X+4 ) =26.6 - X,(40) 81x - 342=76 (x - 2)(42) 15( 5.5 - x) =2x(47) 30%x+85=70%x+25 ,(46) 8 ( x- 2) =2 (x+7 ),(51) (10- x)吃=5x - 7(43) 16+x=12+2x+x(48) 8.5X1.2 - 5.3x=8.5 - 4x(44) 2 ( x- 4) =3 (x - 12)(49) 5x - 2 ( 3- 2x) =16x - 23(50) (x - 5) >5 - 9= (x- 12) X12(45) 0.4- (4 - x) =1 呜(

5、52) 2.7x - 1.8=1.2x+2.7 ,(56) 3.5x+2=4x - 1,(61) 6 (x+1 ) =0.5 (10x+16),(53) 8 - 5 (6x+0.7) =10x+0.5 ,(58) X+ (3X - 16)吃5%=10 ( X+1 )(59)75-(x+10 ) =2,(54) 8.5x- 3.9x=55.2 (x- 18),(55) 122 - x- 19= (x - 19) X5,(60) 5x - 3X (28 - x) =12+2x ,(62) 5 (x+2) =4 (x+9),(67) 4x - 2 ( 5.5- x) =3.5x - 8,(63) 1

6、27.5- (2x+3) =15,(68) 2.8x=19.32 - 6.4x,(66) 7 ( x+6)- 3x=4 (2x+5 ),(71) 2.6x=51.6 - 3.4x,(64) 3 (x+2) =4 (x+1),(65) 8 ( x- 1.5) =x+0.6 ,(69) 5 (y - 4)- 7 ( 7- y)- 9=12 - 3 (9 - y),(70) 35 (x - 2) - 15 ( 5x - 6) =22x - 63 - 21 ( 3x- 4),(72) 3 ( 4x- 2 2 (3x+3 ) =9 - 8x,(77) ( 0.6X+420 ) -(x+20) =3,(7

7、3) 20+4x=6x - 24,(78) 35 (2 - x) +15 (6 - 5x) =22x+7+21-3x),(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)：x=4.9+ ' x,35(76) 0.4 (x - 0.2) +1.5=0.7x - 0.38,(81) 3x+5 X =2x+ X',44 3(82) X £.2= (18 - x)弋,(91)-2,2(87) ( 9+21 ) x=66x WO-

8、 40 - 440,(83) 4 ( 4x- 6) =5 (3x+1 ),(88) x- 2.5= (x- 1.8) >2(84) 10X=3 (2X+17) +45,(89) 12+ ( x- 12) > + 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)3X-22X+3 _3X+2:=小学复杂方程专91题参考答案:(1) 2x+5=5x - 7 ,2x+5 - 2x=5x - 7 - 2x,3x - 7=5 ,3

9、x - 7+7=5+7 ,3x=12 ,3x -3=12 七,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 3=18 3,x=2.25 ;.8x+-=8,1.8x+上-=8 -5 551.8x=7.2 ,1.8x + .8=7.2 3.8 ,x=4(6) X+ (3X -16)3 =10 (X+1 ),X+(3X -16)4X4=10X+10 ,X+12X 64=10X+10 ,13X 64=10X+10 ,13X 64+64=10

10、X+10+64 ,13X=10X+74 ,13X 10X=10X+74 10X ,3X=74 ,3X 33=74 3,(3)y+22厂 3=1-( - -) X24=1 >24,466 (y+2)- 4 ( 2y - 3) =24 ,30 - 2y=24 ,30 2y+2y=24+2y ,2y+24=30 ,2y+24 24=30 24,2y=6 ,2y勺=6吃,y=3(4)5+( X+16.81 )=,X=：3(7)x+1 = -x+3 ,2 2x+11 1 ox=x+3 1x ,2S 22x+1=3 ,x+1 1=3 1,x=2(8) 6 ( 3x 2) 4 (4x 3) =1 8x

11、,18x 12 16x+12=1 8x,18x 16x+8x=0 ,10x=1 ,x=1 30,x=53( X+16.81 ) X( X+16.81 )=匸 X( X+16.81 ),1Hl；1-X (X+16.81 ) =5 ,5-X (X+16.81 ) >=5 X5,5(9) 4 ( x 2) +20x 4=5 (1 2x),4x 8+20x 4=5 10x,24x+10x=5+12 ,34x=17 ,X+16.81=25 ,X+16.81 16.81=25 16.81 ,x=8.19x=17 334 ,x=:;(10) 1.6 3(x 0.45) =5 ,x 0.45=1.6 3

12、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+84,2x+4 3=3x 5,2x+1+5=3x 5+5,35x 70 75x+90-22x+63x=22x 63-63x+84-22x+63xx+20=21 ,X+20-20 =21 20 ,x=1(12 ) x 岀5+0.4=x 七-0.1 ,一x+0.4=x 0.1 ,15121111x+0.4 x= x 0.1 x,151512150.4+0.1x 0.1

13、+0.1 ,0.5 >60= £ >60 ,60x=30 ;2x+6=3x ,2x+6 2x=3x 2x ,x=6 .(17)(18)(13)150.5 4x=7-0.5x150.5 4x+0.5x=7-0.5x+0.5x150.5 3.5x=7 ,150.53.5x+3.5x=7+3.5x ,150.5 7=7+3.5x 7 ,143.5%.5=3.5x £.5 ,x=41x+ ( 3x 16) 勺5%=10 (x+1 ),x+12x 64=10x+10 ,13x 64=10x+10 ,13x 64 10x=10x+10 10x ,3x 64+64=10+64

14、 ,x=-x 1.4=3.6+_x ,431.4 x=3.6+ x33x 1.4=3.6 ,121.4+1.4=3.6+1.4(14) x72=0.25 111x122I51+円25 -1 1x+v:,232 =0.25 ,11(19)1.2 :x=60 ,：=,3 517x232+2 =0.25+211 11irx2-x=1.2 X5 ,3,2 c；x=6'(15)x=95X+7.25=12 2.5X,45X+7.25+2.5X=12 亠2.5X+2.5X ,7.5X+7.25=12,7.5X+7.25 7.25=12 丄-7.25 ,7.5X=5 ,7.5X £.5=5

15、彳5 ,2X=(20) ,'：=8+x,3(.'J X3= ( 8+x) X3 ,5x 2=24+3x ,5x 2 3x=24+3x 3x ,2x 2=24 ,2x 2+2=24+2 ,2x=26 ,2x 煜=26 -2 ,x=13(21) 8 (x 2) =2x+7 ,(16 )2 (x+2 ) 3=3x 5 ,8x 16+16=2x+7+16 ,8x=2x+23 ,8x - 2x=2x+23 - 2x,6x=23 ,6x W=23 W,x=3匚6(22 )6 (x - 3.5) =17.8+2x ,6x 21=17.8+2x ,6x 21 2x=17.8+2x 2x,4x

16、21+21 = 17.8+21 ,4x 韶=38.8 韶，x=9.7 ;X-；(27) 2(X 0 55)7=；：>2(X 0 55) X(X 0.55) =一X (X 770.55):(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 ,1.632 弋.2=0.2x -.2,x=8.16 ;(24 ) ( 9+ X： ( 9 X =5 : 3,3 (9+X ) =5 (9 X ),3 X9+3X=5 X9 5X ,27+3X

17、=45 5X ,3X+5X=45 27,8X=18 ,8X -J=18 -J,X=2.25 ;(25 ) x+ ( 3x 16) -25%=10 (x+2),1x+ (3x 16) - =10x+10 X ,X (X 0.55)=',77：'：X( X - 0.55) X=" ,X 0.55= I ",32X 0.55+0.55=0.46875+0.55X=1.01875 ;x+ ( 3x 16) X=10x+20 ,x+3x X4 16X4=10x+20 ,x+12x 64=10x+20 ,x+12x 10x=20+64 ,3x=84 ,3x -3=84

18、3 ,x=28(X+12 ) X =42 X ,52S'X,八=42 - XX 42 X,224 2424X+ =42 X ,(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 =22 ,x=5.5 ;15(29) =2.5 ,3k+515=2.5 X ( 3x+5 ),7.5x+12.5=15 ,7.5x+12.5 12.5=15 12.5 ,7.5x=2.5 ,7.5x -7.5=2.5 -.5,1x=3(30) 60-(x+10 ) =5

19、60(x+10 ) X (x+10 ) =5(x+10 )5x+50=605x+50 50=60 505x=105x -=10 x=23(31) ( 28 2x) =6 ( x 5)(26)(38 ) - (x+2) =x+14_x=6x - 3024+30=6x+'x2 4x=二42S x 14 27 2 27x=6(32 )64 - (2x - 5) =3264-( 2x - 5) X ( 2x - 5) =32 X ( 2x - 5)64x=160+6464x=22464x -64=224 W4x=3.5(33 ) 81x- 342=76 X (x - 2)81x- 342=76

20、 X< - 15281x- 76x=342 - 1525x=1905x -5=190 苛x=382(34 ) 1 5 (x- 45% ) =2.8 ,51.45 (x- 0.45) =2.8 ,x- 0.45=1.4 5.8,x - 0.45=0.5 ,x - 0.45+0.45=0.5+0.45 ,x=0.95(35 ) 5 (X+4 ) =26.6 - X ,5x+20+x=26 ., 6 - x+x ,6x+20 - 20=26.6 - 20 ,6x -6=6.6 55 ,(36 ) 100X0.5+ (x- 100) X0.4=0.48x0.4x+10=0.48x0.4x+10

21、- 0.4x=0.48x - 0.4x0.08x=100.08x 5).08=10 弋.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=23 3 _x+_=x+14 23 3 3 ,3x+ - =x+1 4 2 22：x=x -423 313x - x=x - - x4 42 4x - + ' =0+：42 22x='x42丄X肖=丄用42x=2(39) 76 (x- 2) =52x - 3276x - 152=52x - 3276x - 152+

22、152=52x - 32+15276x=52x+12076x - 52x=52x+120 - 52x24x=12024x £4=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=1905x j=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+

23、4+913x=1313x 3=13 3x=1 ；(42) 15 -( 5.5 - x) =2x15 - 5.5+x=2x2x - x=9.5x=9.5 ;(43) 16+x=12+2x+x17(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 25=6x 2),7x 2=17 216+x=12+3x3x x=16 122x=4x -2=4 吃x=2

24、(44 ) 2 (x 4) =3 (x 12)2x 8=3x 362x 8 2x=3x 2x 368=x 368+36=x 36+36x=28 ;(45 ) 0.42 ( 4 x) =1 24(D 41.6=4 x1.6+x=4 x+x1.6+x=41.6+x 1.6=4 1.6x=2.4 ;(46 ) 8 (x 2) =2 (x+7 ),8x 16=2x+14 ,8x 16 2x=2x+14 2x,6x 16+16=14+16 ,6x 2=30 2,x=5(47 ) 30%x+85=70%x+25 ,0.3X+85 0.3x=0.7x+25 0.3x ,0.4x+25=85 ,0.4x+25

25、 25=85 25,0.4x=60 ,0.4x 2.4=60 2).4,x=150 ;(48 ) 8.5X1.2 5.3x=8.5 4x10.2 5.3x=8.5 4x10.2 5.3x+5.3x 8.5=8.5 4x+5.3x 8.51.3x=1.71.3x2.3=1.7 2.317x=(50) (x 5) X5 9= (x 12) X25x 25 9=12x 1445x 34=12x 1445x 34 5x+144=12x 144 5x+1447x=1107x 2=110 2110x=7(51) (10 x) 2=5x 710 x=10x 1410 x+x+14=10x 14+x+1411

26、x=2411x 21=24 2124x=-11(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 ,1.5x2.5=4.5 2.5,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 ,4-40=40x 20,x=0.1 ;(54) 8.5x 3.9x=55.2 (x 18),4.6x=55.2x 993.6 ,4.6x 4.6x=55.2x 993.6 4.6

27、x ,50.6x 993.6=0 ,50.6x 993.6+993.6=993.6 ,50.6x=993.6 ,50.6x 20.6=993.6 250.6 , x=19.；7x=17x=33 ;(56) 3.5x+2=4x 1,X=74¥(59)75 - (x+10) =2 ,3.5X+2 3.5x=4x 1 3.5x,2+1=0.5x 1+1 ,3 吒).5=0.5x 却.5,x=6(57)3.5 (X 16) =1.5X ,3.5X 56=1.5X3.5X 56+56=1.5X+563.5X 1.5X=562X=56X=28 ,(58 ) X+ ( 3X 16)七5%=10 (

28、X+1 )X+ (3X 16) >4=10X+10X+3X >4 16>4=10X+1013X 64=10X+1013X 64+64=10X+10+6413X=10X+7413X 10X=10X+74 10X3X=7475-(x+10) X(x+10) =2 X(x+10),2x+20=75 ,2x+20 20=75 20,2x=55 ,2x勺=55煜，x=27.5 ;(60 ) 5x 3X( 28 x) =12+2x , 8x 84=12+2x ,8x 84+84=12+2x+84 ,8x=96+2x ,8x 2x=96+2x 2x,6x=96 ,6x -6=96 -6,x

29、=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=25x+10=4x+36 , 5x 4x=36 10 , x=26 ;(63) 127.5 -( 2x+3 ) =15 ,127.5 -( 2x+3 ) X ( 2x+3 ) =15 X ( 2x+3 ),15X( 2x+3) =127.5,15X( 2x+3 ) -5=127.5 -5 ,2x+3=8.5 ,2x+3 3=8.5 3 ,2x=5.5 ,2x £=5.5,x=2.75 ;(64) 3 (x+2 ) =4 (x+1 ),

30、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 -, 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 -=22 4 ,x=5.5 ;(67) 4x 2 (

31、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=3 ,2.5x吃.5=3 £.5,x=1.2(62) 5 (x+2) =4 (x+9 ),(68 ) 2.8x=19.32 6.4x ,4x=6 ,4x 1=64 ,x=1.5 ;2.8x+6.4x=19.32 6.4x+6.4x ,9.2x=19.32 ,9.2x 电2=19.32 02,x=2.1 ;(75) 3 ( 3x 2) =10 0.5 (x 3.5),(69) 5

32、 (y 4) 7 ( 7 y) 9=12 3 (9 y),5y 20 49+7y 9=12 27+3y ,12y 78=3y 15,12y 78+78=3y 15+78 ,12y 3y=3y+63 3y,9y=63 ,9y -=9=63 -=9,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=19x 6=11.75 0.5x ,9x 6+0.5x=11.75 0.5x+0.5x ,9.5x 6=11.75 ,9.5x 6+6=

33、11.75+6 ,9.5x=17.75 ,9.5x斜5=17.75 用.5,x=47:;(71 ) 2.6x=51.6 3.4x ,2.6x+3.4x=51.6 3.4x+3.4x ,6x=51.6 ,6x -=51.6 x=8.6;(72 ) 3 (4x 2) 2 ( 3x+3 ) =9 8x ,6x 12=9 8x,6x 12+8x=9 8x+8x ,14x 12=9 ,14x 12+12=9+12 ,14x=21 ,14x-4=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

34、 ,2x勺=44勺，x=22 ;(74 ) 5 (x 1) =x+1 ,5x 5=x+1 ,5x 5 x=x+1 x ,4x 5=1 ,4x 5+5=1+5 ,(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 ) =3 X

35、(x+20 ),3 (x+20 ) =0.6x+420 ,3x+60=0.6x+420 , 3x+60 0.6x=0.6x+420 2.4x+60=420 ,2.4x+60 60=420 60 ,2.4x=360 ,2.4x 吃.4=360 £.4 , x=150 ;(78) 35 (2 x) +15 (6 5x) =22x+7+21(4 160 110x=91 41x,160 110x+110x=91 41x+110x , 69x+91=160 ,69x+91 91=160 91 ,69x=69 ,69x 59=69 -69 ,x=1(79) 5 ( 3x 4) 2 ( x 1) =5 ( 2x 1)15x 20 2x+2=10x 5 ,13x 18=10x 5 ,13x 18 10x=10x 5 10x ,3x 18= 5 ,3x 18+18= 5+18 ,3x=13 ,0.6x ,3x),3x -3=13 七,13x=-3(80 )