小數(shù)方程計(jì)算專項(xiàng)練習(xí)題

1、小數(shù)方程計(jì)算專項(xiàng)練習(xí)題小數(shù)方程專項(xiàng)練習(xí)（有答案）(1)(x+0.55)X4=3.6(8)6x8.5X4=20(2)2x+8=0.8(9)36+x=0.4(3)1.5X2+2x=5(10)9.6xx=43(4)4.7x=1.9x+7(11)3x-4X0.9=46.2(5)12.6(x+4.8)+2=63(12)3.5x-4X7=42(6)12.5+4x=21.7(13)x-0.9x=81.913.5x-8.5x=20(14)3.8+5x=12.3第3頁(yè)共19頁(yè)(15) 4 (0.3+x) =6.8(23) 2.5x-20=16(16)8x-1.6x=19.2(24)6.2x-x=41.6第#頁(yè)共

2、19頁(yè)(17)x+1.8=1.62(25)x+0.5=48.6X2(18) 22.5X2+5x=135,(26)5X-7.8=20.2,(19) 1.4x+9.8=22.4,(27)2.5XX=1.8,(20) 2(x3)=11.6,(28)(4.5+X)X2=13,(21) 684.4x=24,(29) 7x2X9=80,(22)1.6X8-5x=2.3(30) 13x-7.5x=18.75(31) (x+12) X 6=108,(39) 2x-2.5X 10=15(32) 4x+3X0.7=6O(40)3.85+1.5x=6.1第5頁(yè)共19頁(yè)(33) 2X(x0.5)=1.6(41) 13

3、(x+2.5)=169(34)3xX2.34=4.914(42) 2x-2+1.8=3.6(35)1.44+x=0.4(43)7(x1.2)=3.57(36)(37)2x+6=12.52.5x-x=1.2(44)2+1.8-2x=3.6(45)7x+0.3=4.2(38)(4.5+x)X2=63(46) 6x+4x-11=32.9(47) 7(x1.2)=2.87(55)3x+7=29.5第7頁(yè)共19頁(yè)(48) 2.4+3.4x=5.8(56)5x-2.8X1.2=1.04(49)5(x1.2)=35(57)4x+6x=28.5(50)2.5x+51=17X8(58)2.38x+9.8=33.

4、6(51)2.4x+1.6x=2.2(59)2(x-3)=10.6(52)8(x6.2)=41.6(60)13x-x=14.4(53)0.5(x0.5)=7.5(61)68-1.1x=24(54)(9x+1.5+7x)+5=5.1(62)3(x+3.5)=21.6(84) 45.34X=35.7,(63)3x54=136.5(70)8-5(6x+0.7)=10x+0.5,(64)(65)(66)(67)(68)(69)x-0.36x=3.24x+2.8X4=19.324x-5.2=5.24.8x+2.6x=3.73x+6.4X2=50.32.7x-1.8=1.2x+2.7,(71)(72)(7

5、3)(74)(75)(76)7+x0.7=13(5.9+x)+3+16=30,0.56X54x=0.4,4(x0.5)=9.62X(x+1.7)=9.28x4x=0.64(77)2x-0.24=0.12第11頁(yè)共19頁(yè)(78) (3.82)x=14.4(80)(82)(83)8.6X 2.6X=36.66X4- 0.6X=6.360.03X 150- 5x=3.2(86)(87)(88)5.9X+7=8.7X ,3+0.6x=4.320.6 (y 0.4) =6(79) 6416X=56.8(85)3(5.4+X)+6=7.2,小數(shù)方程88題參考答案:6.3X (x+4.8) =63(7)13

6、.5x-8.5x=20(8)6x-8.5X4=20(1) (x+0.55)X4=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+8X4=0.8X4x=3.2(3) 1.5X2+2x=53+2x=53+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(x+4.8)+2=636.3X(x+4.8)+6.3=63+6.3x+4.8=10x+4.8-4.8=104.8x=5.2;(6) 12.

7、5+4x=21.712.5+4x-12.5=21.7-12.54x+4=9.2+4x=2.35x+5=20+5x=46x-34=206x-34+34=20+346x+6=54+6x=9(9) 36+x=0.436+xXx=0.4Xx0.1x=81.90.1x+0.1=81.9+0.1第13頁(yè)共19頁(yè)x=819;36=0.4Xx36+0.4=0.4Xx+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

8、.5x-4X7=423.5x-28=42(14) 3.8+5x=12.33.8+5x-3.8=12.3-3.85x=8.55x+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=1.7-0.3x=1.4(16) 8x-1.6x=19.26.4x=19.26.4x+6.4=19.2+6.4,x=3;(17) x+1.8=1.623.5x-28+28=42+283.5x=70(13) x-0.9x=81.93.5x+3.5=70+3.5x=20;x+1.8X1.8=1.62X1.8,x=2.916;5x+5=28 +

9、5,45+5x-45=135- 45,(18) 22.5X2+5x=135,5x+5=90+5,4.4x=44)4.4x+4.4=44+4.4)x=10第17頁(yè)共19頁(yè)x=18.(19) 1.4x+9.8=22.4,1.4x+9.8-9.8=22.4-9.8,1.4x=12.6,(22)1.6X8-5x=2.312.8-5x+5x=2.3+5x2.3+5x-2.3=12.8-2.35x+5=10.5+5x=2.1;(20)1.4x+1.4=12.6+1.4,x=9;2(x-3)=11.6,2x-6=11.6,2x-6+6=11.6+6,2x=17.6,2x+2=17.6+2,x=8.8;(21

10、)68-4.4x=24,68-4.4x+4.4x=24+4.4x,24+4.4x=68,24+4.4x-24=68-24,(23) 2.5x+20=162.5x+20X20=16X202.5x+2.5=320+2.5x=128;(24) 6.2x-x=41.65.2x=41.65.2x+5.2=41.6+5.2x=8;(25) x+0.5=48.6X2x+0.5=97.2x+0.5X0.5=97.2X0.5x=48.6(26) 5X-7.8=20.2,5x-7.8+7.8=20.2+7.8,x=5.6;(27)2.5XX=1.8,(31)(x+12)X6=108,(x+12)X6+6=108+

11、6,1.5x+1.5=1.8+1.5,x+12=18(28)4.5,(29)18+18(30)x=1.2;(4.5+X)X2=13,5+x)X2+2=13+2,4.5+x4.5=6.5x=2.7x2X9=80,7x-18=80,=80+18,7x=98,7x+7=98+7,x=14;13x-7.5x=18.75(137.5)x=18.7(32)2.1(33)5.5x=18.7,5.5x+5.5=18.7+5.5,x=3.4;(34)x+12-12=1x=6.4x+3X0,7=6.54x+2,1=6.4x+2.1-2.1=64x=4.4x+4=4x=1.2X(x0.5)=1.62x-1=12x-

12、1+1=1.6+12x=2.62x+2=2.6+2x=1.33xX2.34=4.9147.02x=4.914x=27;7.02x+7.02=4.914+7.02x=0.7(39)2x-2.5X10=152x-25+25=15+25(35)1.44+x=0.42x+2=40+21.44+xXx=0.4Xxx=20.0.4x=1.44(40)3.85+1.5x=6.10.4x+0.4=1.44+0.43.85+1.5x=6.1(36)(37)x=3.62x+6=12.52x+6-6=12.5-62x+2=6.5+2x=3.25;2.5x-x=1.21.5x=1.21.5x+1.5=1.2+1.5x

13、=0.8;(38)(4.5+x)X2=63(4.5+x)X2+2=63+24.5+x-4.5=31.5-4.53.85-3.85+1.5x=6.1-3.851.5x=2.251.5x+1.5=2.25+x=1.51.5(41)13(x+2.5)=16913(x+2.5)+13=169+13x+2.5=13x+2.5-2.5=13x=11.5(42)2x-2+1.8=3.62x-0.2=3.6-2.52x+0.20.2=3.6+0.22x=3.82x+2=3.8+2x=1.9(47) 7 (x 1.2) =2.87(43)7(x1.2)=3.577(x1.2)+7=2.87+7第19頁(yè)共19頁(yè)7

14、(x1.2)+7=3.57+7x-1.2+1.2=0.41+1.2x=1.61x-1.2=0.51x+1.2-1.2=1.2+0.51(48)2.4+3.4x=5.8x=1.712.4+3.4x-2.4=5.82.4(44)2+1.8-2x=3.63.4x=3.43.82x+2x=3.6+2x3.4x+3.4=3.4+3.43.8-3.6=3.6+2x-3.60.2+2=2x + 2(49) 5 (x 1.2) =35x=0.1;5 (x- 1.2) +5=35+5x-1.2=7(45)7x + 07x+0.3=4.23X 0.3=4.2X 0.3x- 1.2+1.2=7+1x=8.2;.27

15、x+7=1.26+7x=0.18;(50) 2.5x+51=17X82.5x+51=136(46)6x+4x - 11=32.92.5x+51 -51 = 136- 5110x- 11+11=32.9+112.5x=8510x+10=43.9 + 102.5x+2.5=85+2.5x=34.x=4.39;(51)2.4x+1.6x=2.24x=2.2x=1.5;第21頁(yè)共19頁(yè)4x+4=2.2+4(55)3x+7=29.5x=0.55;3x+7-7=29.5-73x=22.5(52)8(x6.2)=41.63x+3=22.5+38(x6.2)+8=41.6+8x=7.5x-6.2+6.2=5.

16、2+6.2x=11.4.(56)5x-2.8X1.2=1045x-3.36=1.04(53)0.5(x0.5)=7.50.5(x0.5)+0.5=7.5+0.53.36+3.36=1.04+3.36(54)x-0.5=155x=4.4x-0.5+0.5=15+0.5x=15.5;(9x+1.5+7x)+5=5.1(16x+1.5)+5=5.1(16x+1.5)+5X5=5.1X516x+1.5=25.516x+1.5-1.5=25.5-1.516x=2416x+16=24+165x+5=4.4+5x=0.88(57)4x+6x=28.510x=28.810x+10=28.5+10x=2.85(

17、58)2.38x+9.8=33.62.38x+9.8-9.8=33.6-9.82.38x+2.38=23.8+2.38x=103x+3=190.5+ 3第23頁(yè)共19頁(yè)(59)2(x3)=10.6x=63.5;2(x-3)+2=10.6+2(60)x-3+3=5.3+3x=8.3;13x-x=14.4(64)x-0.36x=3.20.64x=3.20.64x-0.64=3.2-0.64x=5;12x=14.412x+12=14.4+12(61)68-1x=1.2;68-1.1x=241x+1.1x=24+1.1x68-24=24+1.1x-24(65)4x+2.8X4=19.34x+11.21

18、1.2=19.32-11.24x+4=8.12+4x=2.03.44+1.1=1.1x+1.1(66) 4x-5.2=5.2x=40.4x-5.2+5.2=5.2+5.24x=10.4(62)3 (x+3.5) =21.64x + 4=10.4 + 43 (x+3.5) +3=21.6+3x=2.6;3.5x=3.7;(63)3x-54=136.5x=0.5;x+3.5-3.5=7.2-(67) 4.8x+2.6x=3.77.4x=3.77.4x+7.4=3.7+7.454+54=136.5+54(68) 3x+6.4X 2=50.33x+12,8=50.33x+12.8-12.8=50.3-

19、12.84+40=40x+40,x=0.1;第#頁(yè)共19頁(yè)(70)=10x+3x=37.53x+3=37.5+3x=12.5.(69)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+4.51.2x,1.5x+1.5=4.5+1.5,x=3;8-5(6x+0.7)0.5,8-30x-3.5=10x+0.5,4.5-30x+30x=10x+0.5+30x,4.5-0.5=40x-0.5,(71) 7+x-0.7=137+x-0.7+0.7=1.3+077+xXx=2Xx)7+2=2x+2,x=3.5;(72) (5.9+x)+3

20、+16=30,(5.9+x)+3+16-16=30-16)(5.9+x)+3X3=14X3,5.9+x-5.9=425.9,x=36.1.(73)0.56X5-4x=0.4,2.8-4x=0.4,2.8-4x+4x=0.4+4x)0.4+4x=2.8,0.4+4x- 0.4=2.8 0.4,x=0.16.4x=2.4)4x+4=2.4+4)(77)2x-0.24=0.12x=0.6;2x-0.24+0.24=0.12+0.24第25頁(yè)共19頁(yè)2x=0.36(74)4 (x 0.5) =9.6,2x+2=0.36 + 2x=0.18.4x=11.6)(78) (3.82) x=14.44x + 4=11.6+ 4,1.8x=14.4(75)+ 2=9x=2.9.2X (x+1.7) =9.22X (x+1.7)x+1.7=4.61.8x+1.8=14.4+ 1.8(79) 64- 16X=56.864 一16X+16X=56.8+16Xx+1.7 - 1.7=4.616X+56.8=644x2=9.6,4x-2+2=9.6+251.7x=2.9.16X+56.8-56.8=64-56.816X=7.216X-16=7.2-16X=0.45;(76)8x-4x=0.644x=0.64(80)8.6X-2.6X=36.66X=36.64x+4=0.64+46X +6=36.6+61.3