小数方程计算专项练习题

1、8.9H (x+e.o)寸6曾X6 0 IXZ.9 寸 H6CX 寸 xee 寸 Hx I X9.6)(CL)0)(二)(OL)寸OH杀9" (6)OZH艾 g.8x9 (8)(曙他袒)卜习X寸+gdL"9"甲(8寸+x) 9ZL卜+X6LHX、寸gHX2+3<9L9®艾(gg.o+x)Q)(9)(9)(寸)(e)Q)(16)8x - 1.6x=19.2(25)x0.5=48.6 >2(23)2.5x 吃0=16(24)6.2x - x=41.6(17)xT8=1.62(26)5X - 7.8=20.2,(18)22.5>2+5x=13

2、5 ,(27)2.5X - X=1.8 ,(19)1.4x+9.8=22.4 ,(28)(4.5+X) X2=13,(20)2 ( x- 3) =11.6,(29)7x 2 ><9=80,(21)68 - 4.4x=24 ,(30)13x - 7.5x=18.7 ,(22)1.6X8 - 5x=2.3(31)(x+12) >=108,(32)4x+3 >.7=6.5(33)2X (x - 0.5) =1.6(42)2x - 2+1.8=3.6(41)13 (x+2.5 ) =169(34)3x >2.34=4.914(43)7 (x - 1.2) =3.57(35

3、)1.44 次=0.4(44)2+1.8 - 2x=3.6(36)2x+6=12.5(45)7x 七.3=4.2(37)2.5x - x=1.2(46)6x+4x - 11=32.9(38)(4.5+x) X2=63(47)7 (x - 1.2) =2.87(39)2x - 2.5 >0=15(48)2.4+3.4x=5.8(40)3.85+1.5x=6.1(49)5 (x - 1.2) =35(59)2 (x - 3) =10.6(50)2.5x+51=17 疋(51)2.4x+1.6x=2.2(60)13x - x=14.4(52)8 ( x- 6.2) =41.6(61)68 -

4、1.1x=24(53)0.5 (x - 0.5) =7.5(62)3 (x+3.5) =21.6(54)(9X+1.5+7X )弋=5.1(63)3x - 54=136.5(55) 3x+7=29.5(64)x - 0.36x=3.2(56)5x - 2.8 Xl.2=1.04(65)4x+2.8 >4=19.32(58)2.38x+9.8=33.6(57)4x+6x=28.5(66)4x - 5.2=5.2(67)4.8x+2.6x=3.7(75)2X(x+1.7) =9.2(68)3x+6.4 X2=50.3(69)2.7x 1.8=1.2x+2.7 ,(70)8 5 (6x+0.7

5、) =10x+0.5 ,(71)7畝0.7=1.3,(76)(77)(78)(79)(80)8x 4x=0.642x 0.24=0.12(3.8 2) x=14.464 16X=56.88.6X 2.6X=36.6(72)(5.9+x) £+16=30,(82)6>4 - 0.6X=6.36(73)0.56 >5 4x=0.4 ,(83)0.03 >50 5x=3.2(74)4 ( x 0.5) =9.6 ,(84)45.3 4X=35.7 ,=6,(87) 3+0.6x=4.32(88) 0.6 (y 0.4)(85) 3 ( 5.4+X)七=7.2 ,(86)

6、5.9X+7=8.7X ,x=3.2(3) 1.5 >2+2x=5(6) 12.5+4x=21.73+2x=512.5+4x 12.5=21.7 12.53+2x 3=5 32x=2 吃x=1(4) 4.7x=1.9x+7小数方程88题参考答案:2.8x=72.8x吃.8=7 吃.8x=2.5(1) (x+0.55) >4=3.6(x+0.5) X韶=3.6 -4x+0.5=0.9(5) 12.6 (x+4.8)吃=636.3X (x+4.8)x+0.5 0.5=0.9 0.5x=0.4(2) 2x 充=0.8=636.3X( x+4.8 ) -6.3=63 七.3x+4.8=10

7、2x 吒 >4=0.8 X4.7x 1.9x=1.9x - 1.9x+7x+4.8 4.8=10 4.8x=5.2 ;4x *9.2 韶x=2.3(7) 13.5x 8.5x=205x弋=20 Px=4(17) xT8=1.62(8) 6x - 8.54=20x-.8X1.8=1.62 >.8,x=2.916 ;6x - 34=206x - 34+34=20+34(18)22.5 >2+5x=135 ,6x£=54 七x=9(9) 36 畝=0.436 畝 X=0.4 X(19)45+5x - 45=135 - 45,5x -5=905,x=18.1.4x+9.8=

8、22.4 ,36=0.4 >x360.4=0.4 >(电4x=90 ;1.4x+9.8 - 9.8=22.4 - 9.8 ,1.4x=12.6,1.4x 4=12.6 T4,x=9 ;(10) 9.6x - x=43(9.6 - 1) x=438.6x £.6=43 充.5(20)(11)3x(13)x=5 ;3x - 4 >.9=46.23x - 3.6=46.22 (x - 3) =11.6,2x - 6=11.6,2x - 6+6=11.6+6 ,2x=17.6 ,2x 吃=17.6 吃,x=8.8;-3.6+3.6=46.2+3.63x£=49.8

9、 七x=16.63.5x - 4 =423.5x - 28=423.5x - 28+28=42+283.5x=703.5x £.5=70 £.5x=20;x - 0.9x=81.90.1x=81.90.1x 4).1=81.9 0.1x=819 ;(14) 3.8+5x=12.33.8+5x - 3.8=12.3 - 3.85x=8.55x为=8.5弋x=1.7 ;(15) 4 ( 0.3+x) =6.84 (0.3+x)韶=6.8韶0.3+x=1.70.3+x - 0.3=1.7 - 0.3x=1.4(16) 8x - 1.6x=19.2 6.4x=19.2,6.4x&#

10、163;.4=19.2 吒.4,x=3 ;(21)68 - 4.4x=24 ,68 - 4.4x+4.4x=24+4.4x , 24+4.4x=68 , 24+4.4x - 24=68 - 24, 4.4x=44 ,4.4x-4.4=44 -4.4,x=10(22) 1.6X8- 5x=2.312.8 - 5x+5x=2.3+5x2.3+5x - 2.3=12.8 - 2.35x 弋=10.5 弋x=2.1 ;(23) 2.5x 吃0=162.5x 吃0X20=16 X202.5x吃.5=320 吃.5x=128;(24) 6.2x - x=41.65.2x=41.65.2x 弋.2=41.6

11、 弋.2x=8 ;(25) x0.5=48.6 Xx 七.5X).5=97.2 X).5x=48.6(26) 5X - 7.8=20.2 ,5x - 7.8+7.8=20.2+7.8 ,5x为=28为,x 0.5=97.2x=5.6;(27) 2.5X - X=1.8 ,x=3.6(36) 2x+6=12.51.5x .5=1.8 勻.5,2x+6 - 6=12.5 - 6x=1.2 ;(28) (4.5+X ) X2=13,2x吃=6.5吃x=3.25 ;(4.5+x) X2 吃=13 吃，4.5+x - 4.5=6.5 - 4.5,(37) 2.5x - x=1.2x=2.1.5x=1.2

12、7.02x=4.914x+1.2 - 1.2=1.2+0.517.02x £.02=4.914 -7.02x=1.71x=0.7(44) 2+1.8 - 2x=3.63.8 - 2x+2x=3.6+2x1.5x 宁1.5=1.2 勻.5(29) 7x - 2 >9=80,x=0.8;7x - 18=80,7x- 18+18=80+18 ,7x=98,(38) (4.5+x) X2=637x -7=987,(4.5+x) X2吃=63吃x=14;4.5+x - 4.5=31.5 - 4.5x=27 ;(30) 13x - 7.5x=18.7 ,(13 - 7.5) x=18.7

13、,5.5x=18.7,(39) 2x - 2.5X10=152x - 25+25=15+255.5x h5.5=18.7 弋.5,2x吃=40吃x=3.4 ;x=20 .(40) 3.85+1.5x=6.1(31) (x+12) 0=108,3.85+1.5x=6.1(x+12) 0=108七,3.85 - 3.85+1.5x=6.1 - 3.85(32)(33)x+12=18,1.5x=2.25x+12 - 12=18 - 12,x=6.1.5x .5=2.25 出.5x=1.54x+3 >.7=6.54x+2.1=6.54x+2.1 - 2.1=6.5 - 2.14x=4.44x詔=

14、4.4呜x=1.12X (x - 0.5) =1.62x - 1=1.62x - 1+1=1.6+12x=2.62x吃=2.6吃(41)13(42)13 (x+2.5) =169(x+2.5 )勻3=169 出3x+2.5=13x+2.5 - 2.5=13 - 2.5x=11.52x - 2+1.8=3.62x - 0.2=3.62x+0.2 - 0.2=3.6+0.22x=3.82x吃=3.8吃x=1.9x=1.3(43) 7 (x - 1.2) =3.57 7 (x- 1.2) £=3.57叼(34)3x >2.34=4.914x - 1.2=0.51(35) 1.447(

15、=0.43.8 - 3.6=3.6+2x - 3.61.44 -7： >=0.4 X0.27=2x 吃0.4x=1.44x=0.1 ;0.4x 7).4=1.44 7).4(45) 7x 七.3=4.2(16X+1.5)为=5.17x 电3 X).3=4.2 >0.3(16X+1.5)为 X5=5.1 X57x £=1.26 叼16x+1.5=25.50.5 (x-0.5)弋.5=7.5 弋.53 (x+3.5)七=21.6七x- 0.5=15x+3.5-3.5=7.2 - 3.5x - 0.5+0.5=15+0.5x=3.7;x=0.18 ;16X+1.5 - 1.5=

16、25.5 - 1.516x=24(46) 6x+4x - 11=32.916x 丸=24 宁1610x - 11+11=32.9+1110x 也=43.9 W0x=1.5 ;(55) 3x+7=29.5x=4.39;3x+7 - 7=29.5 - 73x=22.53x £=22.5 七(47) 7 ( x- 1.2) =2.87x=7.57 (x - 1.2) £=2.87 叼x- 1.2+1.2=0.41+1.2x=1.61(56) 5x - 2.8X1.2=1.04(48) 2.4+3.4x=5.85x - 3.36=1.042.4+3.4x - 2.4=5.8 - 2

17、.45x - 3.36+3.36=1.04+3.363.4x=3.45x=4.43.4x 七.4=3.4七.45x为=4.4为x=1 ；x=0.88(49) 5 ( x- 1.2) =35(57) 4x+6x=28.55 (x - 1.2)为=35 弋10x=28.8x - 1.2=710x 也=28.5 宁10x- 1.2+1.2=7+1.2x=8.2 ;x=2.85(58) 2.38x+9.8=33.62.38x+9.8 - 9.8=33.6 - 9.8(50) 2.5x+51=17 X32.38x 吃.38=23.8 吃.382.5x+51=1362.5x+51 - 51=136 - 5

18、1x=10(59) 2 (x - 3) =10.62.5x=852 (x- 3)吃=10.6吃2.5x 吃.5=85 吃.5x - 3+3=5.3+3x=34 .(51) 2.4x+1.6x=2.2x=8.3;(60) 13x - x=14.44x=2.212x=14.44x *2.2 呜12x 出 2=14.4 勻 2x=0.55;x=1.2 ;(61) 68 - 1.1x=24(52) 8 ( x- 6.2) =41.668 - 1.1x+1.1x=24+1.1x8 (x - 6.2) £=41.6 充68 - 24=24+1.1x - 24x - 6.2+6.2=5.2+6.2

19、441.1=1.1x .1(53)x=11.4 .x=40.0.5 (x - 0.5) =7.5(62) 3 (x+3.5)=21.6x=15.5;(54)(9x+1.5+7x )弋=5.1(63) 3x - 54=136.53x - 54+54=136.5+543x £=190.5 七x=63.5;(64) X- 0.36x=3.20.64x=3.2(5.9+x) £+16 - 16=30 - 16,(5.9+x) -3X3=14X3,5.9+x - 5.9=42 - 5.9, x=36.1 .(73) 0.56 X)- 4x=0.4 ,0.64X -.64=3.2 弋.

20、64x=5 ;(65) 4X+2.8 X4=19.324X+11.2 - 11.2=19.32 - 11.24x-l=8.12 韶x=2.03.(66) 4x - 5.2=5.22.8 - 4x=0.4 ,2.8 - 4x+4x=0.4+4x ,0.4+4x=2.8 ,0.4+4X - 0.4=2.8 - 0.4,4x=2.4,4x -4=2.4 韶，x=0.6 ;4x - 5.2+5.2=5.2+5.2(74)4 (X - 0.5) =9.6 ,4x=10.44X-M0.4 -4x=2.6;(67) 4.8x+2.6x=3.77.4x=3.7(75)4x - 2=9.6,4x - 2+2=9

21、.6+2 , 4x=11.6,4x -4=11.6 -4,x=2.9 .2X (x+1.7) =9.27.4x彳4=3.7 彳4x=0.5;2X (x+1.7) -=9.2吃x+1.7=4.6x+1.7 - 1.7=4.6 - 1.7(68) 3x+6.4 X2=50.3x=2.9.3x+12.8=50.33X+12.8 - 12.8=50.3 - 12.8(76)8x - 4x=0.643x=37.54x=0.643x£=37.5 -4x 4=0.64 -4x=12.5.(69) 2.7x - 1.8=1.2x+2.7 ,x=0.16 .2.7x- 1.8+1.8=1.2x+2.7

22、+1.8 ,2.7x - 1.2x=1.2x+4.5 - 1.2x,1.5x -.5=4.5 -.5,x=3;(77) 2x - 0.24=0.122x - 0.24+0.24=0.12+0.242x=0.362x 吃=0.36 吃x=0.18 .(70)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 -40,x=0.1 ;(78) ( 3.8 - 2) x=14.41.8x=14.41.8x -.8=14.4 -.8x=8 .(79) 64 - 16X=56.8(71)7-< - 0.7=1.3,64 - 16X+16X=56.8+16X16X+56.8=647-(-0.7+0.7=1.3+0.7 ,7-(*=27吃=2x吃，x=3.5 ;16X+56.8 - 56.8=64 - 56.816X=7.216X -6=7.2 -6X=0.45 ;(72)(5.9+x) £+16=30,(80) 8.6X - 2.6X=36.66X=36.66X作36.6七X=2.5 .(87) 3+0.6x=4.32X=6.1