小数方程计算专项练习题

1、小数方程专项练习（有答案）(17) x-1.8=1.62(16) 8x 1.6x=19.2(1) (x+0.55) X 4=3.6(18) 22.5 X2+5x=13§(2) 2x-8=0.8(19) 1.4x+9.8=22.4 ,(3) 1.5 X2+2x=5(20) 2 (x 3) =11.6,(4) 4.7x=1.9x+7(21) 68 4.4x=24,(5) 12.6 (x+4.8) +2=63(22) 1.6 XV 5x=2.3(6) 12.5+4x=21.7(23) 2.5x+20=16(7) 13.5x 8.5x=20(24) 6.2x x=41.6(8) 6x 8.5

2、 X4=20(25) x+0.5=48.6 X2(9) 36 + x=0.4(26) 5X 7.8=20.2 ,(10) 9.6x x=43(27) 2.5X X=1.8,(11) 3x 4X0.9=46.2(28) ( 4.5+X) X2=13(12) 3.5x 4X7=42(29) 7x 2X9=80(13) x 0.9x=81.9(30) 13x 7.5x=18.7,(14) 3.8+5x=12.3(31) ( x+12) X6=108(15) 4 (0.3+x) =6.8(32) 4x+3X0.7=6.5(33) 2X (x 0.5) =1.6(49 ) 5 (x 1.2) =35(3

3、4) 3xX 2.34=4.914(50 ) 2.5x+51=17X8(35) 1.44 -x=0.4(51) 2.4x+1.6x=2.2(36) 2x+6=12.5(52) 8 (x 6.2) =41.6(37) 2.5x x=1.2(53 ) 0.5 (x 0.5) =7.5(38) ( 4.5+x ) X2=63(54) ( 9x+1.5+7x ) +5=5.1(39) 2x 2.5 X 10=15(55 ) 3x+7=29.5(40) 3.85+1.5x=6.1(56 ) 5x 2.8 X 1.2=1.04(57) 4x+6x=28.5(41 ) 13 (x+2.5 ) =169(42

4、) 2x 2+1.8=3.6(58 ) 2.38x+9.8=33.6(59 ) 2 (x 3 ) =10.6(43) 7 (x 1.2) =3.57(60 ) 13x x=14.4(44) 2+1.8 2x=3.6(45) 7x+0.3=4.2(61) 68 1.1x=24(46) 6x+4x 11=32.9(62) 3 (x+3.5) =21.6(63 ) 3x 54=136.5(47) 7 (x1.2) =2.87(48) 2.4+3.4x=5.8(64 ) x 0.36x=3.2(77) 2x 0.24=0.12(78) ( 3.8 2) x=14.4(79) 64 16X=56.8(8

5、0) 8.6X 2.6X=36.6(82) 6X4 0.6X=6.36(83) 0.03 X 150 5x=3.2(84) 45.3 4X=35.7,(85) 3 (5.4+X) +6=7.2(86) 5.9X+7=8.7X,(87) 3+0.6x=4.32(88) 0.6 (y 0.4) =6,(65) 4x+2.8 X 4=19.32(66) 4x 5.2=5.2(67) 4.8x+2.6x=3.7(68) 3x+6.4 X 2=50.3(69) 2.7x 1.8=1.2x+2.7 ,(70) 8 5 (6x+0.7) =10x+0.5,(71 ) 7+0.7=1.3 ,(72) ( 5.

6、9+x) +3+16=30(73) 0.56 X 夕 4x=0.4 ,(74) 4 (x 0.5) =9.6,(75) 2X (x+1.7) =9.2(76) 8x 4x=0.64小数方程88题参考答案:(1) (x+0.55) X 4=3.6(x+0.5) X4+4=3.6+4x+0.5=0.9x+0.5 0.5=0.9 0.5x=0.4(2) 2x-8=0.82x+ 8X 4=0.8 X 4x=3.23+2x 3=5 32x +2=2+2x=1(4) 4.7x=1.9x+74.7x 1.9x=1.9x 1.9x+72.8x=72.8x + 2.8=7 + 2.8x=2.5(5) 12.6

7、(x+4.8) +2=636.3 X(x+4.8) =636.3 X(x+4.8) +6.3=63 +6.3 x+4.8=10(3) 1.5 X2+2x=53+2x=5x+4.8 4.8=10 4.8 x=5.2;(6) 12.5+4x=21.712.5+4x 12.5=21.712.54x +4=9.2 +4x=2.3(7) 13.5x 8.5x=205x + 5=20 + 5x=4(8) 6x 8.5 X4=206x 34=206x 34+34=20+346x + 6=54 + 6x=9(9) 36 + x=0.436 + xX x=0.4 X x36=0.4 X x36+0.4=0.4

8、X x- 0.4x=90;(10) 9.6x x=43(9.6 1) x=438.6x + 8.6=43 + 8.5x=5;(11) 3x 4X0.9=46.23x 3.6=46.23x 3.6+3.6=46.2+3.63x+ 3=49.8 + 3x=16.6(12) 3.5x 4X7=423.5x 28=423.5x 28+28=42+283.5x=703.5x + 3.5=70 + 3.5 x=20;(13) x 0.9x=81.90.1x=81.90.1x + 0.1=81.9 + 0.1x=819;(14) 3.8+5x=12.33.8+5x 3.8=12.3 3.85x=8.55x+

9、 5=8.5 + 5x=1.7;(15) 4 (0.3+x) =6.84 (0.3+x) + 4=6.8 + 40.3+x=1.70.3+x 0.3=1.7 0.36.4x=19.2,6.4x +6.4=19.2 十 6.4x=3;(17) x-1.8=1.62x+ 1.8 X 1.8=1.62 ,X 1.8 x=2.916;(18) 22.5 X2+5x=13§45+5x 45=135 45,5x + 5=90 亍 5x=18.(19) 1.4x+9.8=22.4 ,1.4x+9.8 9.8=22.4 9.8,1.4x=12.6 ,1.4x + 1.4=12.6 宁 1.4x=9;

10、(20) 2 (x 3) =11.6,2x 6=11.6,2x 6+6=11.6+6,2x=17.6,2x+ 2=17.6 ,- 2x=8.8;(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 方 4.4 x=10(22) 1.6 XV 5x=2.312.8 5x+5x=2.3+5x2.3+5x 2.3=12.8 2.35x+ 5=10.5 + 5x=2.1;(23) 2.5x+20=162.5x - 20X 20=16 X 202.5x + 2.5=320 + 2.5

11、x=128;(24) 6.2x x=41.65.2x=41.65.2x +5.2=41.6 +5.2x=8;(25) x+0.5=48.6 X2x+ 0.5=97.2x+ 0.5 X 0.5=97.2 X 0.5x=48.6(26) 5X 7.8=20.2 , 5x 7.8+7.8=20.2+7.8 ,x=1.4(16) 8x 1.6x=19.25x + 5=28 亍 5x=5.6;(27) 2.5X X=1.8, 1.5x + 1.5=1.8 十 1.5 x=1.2;(28) (4.5+X) X2=13 (4.5+x) X 2+2=13广2 4.5+x 4.5=6.5 4.5, x=2.(2

12、9) 7x 2X9=80 7x 18=80, 7x 18+18=80+18, 7x=98, 7x + 7=98 亍 7 x=14;(30) 13x 7.5x=18.7, (13 7.5) x=18.7, 5.5x=18.7 , 5.5x + 5.5=18.7 宁 5.5 x=3.4;(31) (x+12) X 6=108 (x+12) X 6- 6=108,-6 x+12=18, x+12 12=18 12, x=6.(32) 4x+3X0.7=6.5 4x+2.1=6.5 4x+2.12.1=6.5 2.14x=4.44x + 4=4.4 + 4x=1.1(33) 2X (x 0.5) =1

13、.62x 1=1.62x 1+1=1.6+1 2x=2.62x + 2=2.6 + 2x=1.3(34) 3xX 2.34=4.914 7.02x=4.914 7.02x + 7.02=4.914 + 7.02 x=0.7(35) 1.44 -x=0.41.44 + x X x=0.4 X x 0.4x=1.44 0.4x +0.4=1.44 +0.4 x=3.6(36) 2x+6=12.5 2x+6 6=12.5 6 2x + 2=6.5 + 2 x=3.25;(37) 2.5x x=1.21.5x=1.21.5x + 1.5=1.2 + 1.5 x=0.8;(38) (4.5+x) X2=

14、63 (4.5+x) X 2+2=63+ 2 4.5+x 4.5=31.5 4.5 x=27;(39) 2x 2.5 X 10=15 2x 25+25=15+25 2x + 2=40 + 2 x=20.(40) 3.85+1.5x=6.13.85+1.5x=6.13.85 3.85+1.5x=6.13.851.5x=2.251.5x + 1.5=2.25 + 1.5 x=1.5(41) 13 (x+2.5) =16913 (x+2.5) + 13=169 + 13 x+2.5=13x+2.5 2.5=13 2.5 x=11.5(42) 2x 2+1.8=3.62x 0.2=3.62x+0.2

15、0.2=3.6+0.22x=3.82x+ 2=3.8 + 2x=1.9(43) 7 (x 1.2) =3.577 (x 1.2) + 7=3.57 + 7x 1.2=0.51x+1.2 1.2=1.2+0.51 x=1.71(44) 2+1.8 2x=3.63.8 2x+2x=3.6+2x3.8 3.6=3.6+2x 3.6 0.2 + 2=2x + 2x=0.1;(45) 7x+0.3=4.27x+ 0.3 X 0.3=4.2 X 0.37x + 7=1.26 + 7x=0.18;(46) 6x+4x 11=32.910x 11 + 11=32.9+1110x+ 10=43.9 + 10x=

16、4.39;(47) 7 (x 1.2) =2.877 (x 1.2) + 7=2.87 + 7x 1.2+1.2=0.41 + 1.2x=1.61(48) 2.4+3.4x=5.82.4+3.4x 2.4=5.8 2.43.4x=3.43.4x + 3.4=3.4 + 3.4 x=1;(49) 5 (x 1.2) =355 (x 1.2) + 5=35 + 5x 1.2=7x 1.2+1.2=7+1.2x=8.2;(50) 2.5x+51=17X82.5x+51=1362.5x+51 51=136 512.5x=852.5x + 2.5=85 + 2.5x=34.(51) 2.4x+1.6x=

17、2.24x=2.2 4x +4=2.2 +4x=0.55;(52) 8 (x 6.2) =41.68 (x 6.2) + 8=41.6 + 8x 6.2+6.2=5.2+6.2 x=11.4 .(53) 0.5 (x 0.5) =7.50.5 (x 0.5) + 0.5=7.5 + 0.5x 0.5=15x 0.5+0.5=15+0.5 x=15.5;(54) (9x+1.5+7x) +5=5.1 (16x+1.5) +5=5.1 (16x+1.5) + 5X 5=5.1 X 5 16x+1.5=25.516x+1.5 1.5=25.5 1.5 16x=2416x+ 16=24 + 16 x=

18、1.5;(55) 3x+7=29.53x+7 7=29.5 73x=22.53x + 3=22.5 + 3x=7.5(56) 5x 2.8 X 1.2=1.045x 3.36=1.045x 3.36+3.36=1.04+3.36 5x=4.4(57) 4x+6x=28.510x=28.810x+ 10=28.5 + 10x=2.85(58) 2.38x+9.8=33.62.38x+9.8 9.8=33.6 9.82.38x + 2.38=23.8 + 2.38 x=10(59) 2 (x 3) =10.62 (x 3) + 2=10.6 + 2x 3+3=5.3+3 x=8.3;(60) 13

19、x x=14.412x=14.412x+ 12=14.4 + 12x=1.2;(61) 68 1.1x=2468 1.1x+1.1x=24+1.1x68 24=24+1.1x 2444 + 1.1=1.1x + 1.1x=40.(62) 3 (x+3.5) =21.63 (x+3.5) +3=21.6 +3x+3.5 3.5=7.2 3.5 x=3.7;(63) 3x 54=136.53x 54+54=136.5+543x+3=190.5 +3x=63.5;(64) x 0.36x=3.20.64x=3.20.64x + 0.64=3.2 + 0.64x=5;(65) 4x+2.8 X 4=1

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