六年级解方程专项练习题有答案
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(1)x﹣=,
(2) x××=,
(3) ﹣4x=,
(4)
8×﹣2x=
(5)
:x=3:5,
(6)1﹣20%x=,
(8)
1÷(x﹣)=6,
(9)2x﹣x=,
六年级解方程专项练习200题(有答案)
(10)9×3﹣=,
(11)x﹣25%x=24,
(12)x﹣+=,
(13)+90%x=78,
(14)20%x﹣×3=,
(15)x﹣x=42,
(16)+3×=,
(17)1÷(x﹣)=5,
(18)x﹣=,
(19):x=3:12,
(20)x+=,
(21) :x=1:,
(22) x×(2﹣)=24,
(23) 4x﹣=3,
(24)12x+7×=,
(25)x+x=,
(26)x:42=,
(27)×+x=,
(28):=:x,
(29)χ﹣χ=,
(30)42:=χ:
(31)5x﹣=75%,
( 32)
6x﹣=,
(33)2(x﹣3)=,
(34) =,
(35) 4x﹣3×9=29,
(36)16+8x=40,
(37) x÷=3,
(38)+2x=,
(39)×3﹣7x=,
(40)x﹣1﹣x=2,
(41)x﹣x=14,
(42)3x﹣x=,
(43)=,
(44):=,
(45)=:,
(46):=x:,
(47)x=+1,
(48)1﹣25%X+25%x=+25%x,
=,
(49)
×X=,
(50)
(51)
5:8=x:32,
(52)2x+3×=,
(53)﹣=,
(54)×(7﹣)=,
(55)x:=:,
(56)150%x+66=99
(57)x+6﹣=16
(58)
(59)
(60)3÷(X﹣)=
(61)(X+):2=(X﹣4):,
(62) X÷=,
(63)2X﹣4×6=80,
(64)4×﹣3X=,
(65)4X﹣=10,
(66)+X=20,
(67)×12+15X=,
(68)6X+5=17,
(69)×(+X)=,
(70):=X:,
(71),
(72)
(73),
(74)4(+x)=,
(75)×+x=,
(76)x﹣,
(77)200:6=x:,
(78)4÷X=,
(79)8(x﹣2)=2(x+7),
(80):18%=,
﹣2x=,
(81)
x+x=46,
(82)
(83):x=:,
(84)=,
(85)5(3x﹣4)﹣2(x﹣1)=5(2x﹣1)
(86)=,
(87)8(2X﹣7)=5(X+13),
(88)3(x+)=60,
(89)+=,
(90)3(x﹣)=,
(91)﹣5x=,
(92)x:=
(93)+2x=,
(94)x=15%,
(95)x﹣x=,
(96)x+50%x=6,
(97):x=:12,
(98)4x+2(8﹣x)=26,
(99)x﹣=0,
(100)+x=1,
(101)x×(+)=,
(102),
(103),
(104)x﹣,
(105)x×,
(106)5x+35=650,
(107)720÷3x=80,
(108)﹣=,
(109)4×﹣3x=6,
(110)=,
(111)6×3﹣=,
(112)÷x=,
(113)x÷=42,
(114)x+=,
(115)7x÷3=,
(116)12:=x:,
(117)3(x+2)=4(x+1),
(118)3x﹣70%x=,
(119) 6+x=240,
(120)﹣=,
(121)x:=4:2,
(122)x﹣﹣6=16,
(123):=x:8,
(124),
(125)x:15=:,
(126)x+x=,
(127)x×50%﹣x=5,
(128)1﹣x=,
(129)+1x=3,
(130)3x﹣2=4,
(131)﹣3x=2,
(132)3÷x=4,
(133)x﹣5%=,
(134):=:(4﹣x),
(135) 6x+31=49,
(136) 7x÷3=,
(137) ﹣9x=,
(138) x﹣=16,
(139) 6×7+3x=69,
(140) 6x+2x﹣56=0,
(141) 3x﹣×4=,
(142) ﹣=,
(143) ÷(9﹣x)=3,
(144) 3x÷=8,
(145)5x+28=71,
(146)﹣=,
(147)8x﹣=,
(148)﹣×4=,
(149)54÷2+3x=72,
(150)8x﹣=,
(151)x÷=,
(152)x+30%x=26,
(153) ﹣3x=,
(154)
6×3﹣=,
(155)10:x=:,
(156):=x:,
(157)X﹣=,
(158)﹣X=,
(159)X﹣(+)=,
(160)÷x=,
(161)=,
(162)x﹣80%x=48,
(163)75%x﹣5×=6,
(164)x﹣=,
(165)=,
(166)﹣y=,
(167)5x+=,
(168) x﹣=,
(169) 9x+5x=,
(170) +=,
(171)5÷x=,
(172)﹣x=,
(173)×﹣3x=,
(174)(1+25%)x=,
(175)x﹣40%x=9,
(176)x×20%=,
(178)x﹣x=,
(179)x÷75%=3,
(180)4x﹣,
(181):x=:,
(182)(x﹣)×6=,
(183)27﹣17x=,
(184)+3x=×5,
(185)2x+5=5x﹣7,
(186) 3(x﹣2)=2﹣5(x﹣2),
(187)4x﹣3(20﹣x)+4=0,
(188)﹣=1,
(189)4x﹣5×6=12,
(190)8x﹣3x=,
(191)30×(x÷4)=60,
(192)×﹣3x=,
(193)5x﹣×5=8,
(194)+x=×2,
(195)5x+×15=66,
(196)+=1,
(197)×16-8x=12,
(198)=,
(199)5(x+6)=75,
(200)x÷+×3=4,
解方程专项练习200题
答案:
(1)x﹣=,
=,
,
x=;
(2) x××=,
x=,
x×21=×21,
x=12;
(3) ﹣4x=,
﹣4x+4x=+4x,
=+4x,
÷4=4x÷4,
x=.
(4) 8×﹣2x=
20﹣2x=,
+2X=20,
2X=,
x=;
(5) :x=3:5,
3x=×5,
3x=,
x=
(6)1﹣20%x=,
1﹣20%x+20%x=+20%x,
+20%x=1,
+20%x﹣=1﹣,
20%x=,
20%x×=×,
x=3;
(8) 1÷(x﹣)=6,
1÷(x﹣)×(x﹣)=6×(x﹣),
1=6×(x﹣),
6x﹣6×=1,
6x﹣3=1,
6x=4,
6x÷6=4÷6,
x=
(9)2x﹣x=,
x(2﹣)=,
x=,
x÷=÷,
x=1;
(10)9×3﹣=,
27﹣=,
27﹣+=+,
+=27,
+﹣=27﹣,
=,
÷=÷,
x=8
(11)x﹣25%x=24,
75%x=24,
75%x÷75%=24÷75%,
x=32;
(12)x﹣+=,
x﹣=,
x﹣+=+,
x=,
x÷=÷,
x=1
(13)+90%x=78,
=78,
÷=78÷,
x=52;
(14)20%x﹣×3=,
20%x﹣=,
20%x﹣+=+,
20%x÷20%=8÷20%,
x=40;
(15)x﹣x=42,
x=42,
x÷=42÷,
x=252
(16)+3×=,
+=,
+﹣=﹣,
=60,
÷=60÷,
x=100;
(17)1÷(x﹣)=5,
÷(x﹣)×(x﹣)=(x﹣),
x﹣=,
x﹣+=+,
x=4,
x÷=4÷,
x=
(18)x﹣=,
x﹣+=+,
x=;
(19):x=3:12,
3x=×12,
3x÷3=9÷3,
x=3
(20)x+=,
x+﹣=﹣,
x=,
x×=×,
x=8.
(21) :x=1:,
x=×,
x=
(22) x×(2﹣)=24,
x×=24,
x×÷=24÷,
x=20;
(23)
4x﹣=3,
4x﹣+=3+,
4x=4,
4x÷4=4÷4,
x=1
(24)12x+7×=,
12x+=,
12x+﹣=﹣,
12x÷12=18÷12,
x=;
(25)x+x=,
x=,
x×,
x=;
(26)x:42=,
10x=42×,
10x÷10=30÷10,
x=3
(27)×+x=,
+x=,
+x﹣=﹣,
x=3,
x÷=3÷,
x=6;
(28):=:x,
=×,
=,
÷=÷,
x=
(29)χ﹣χ=,
x=,
x=,
x=3;
(30)42:=χ:
x=42×,
x=30,
x=50;
(31)5x﹣=75%,
5x﹣+=75%+,
5x÷5=÷5,
x=
( 32)
6x﹣=,
6x﹣+=+,
6x=,
6x÷6=÷6,
x=;
(33)2(x﹣3)=,
2(x﹣3)÷2=÷2
x﹣3=,
x﹣3+3=+3,
x=;
(34) =,
÷=÷,
x=4;
(35) 4x﹣3×9=29,
4x﹣27=29,
4x﹣27+27=29+27,
4x=56,
4x÷4=56÷4,
x=14;
(36)16+8x=40,
16+8x﹣16=40﹣16,
8x=24,
8x÷8=24÷8,
x=3;
(37)
x÷=3,
x÷×=3×,
x=
(38)+2x=,
+2x=,
2x=,
2x÷2=÷2,
x=;
(39)×3﹣7x=,
﹣7x=,
﹣7x﹣=﹣,
﹣7x=0,
7x÷7=÷7,
x=;
(40)x﹣1﹣x=2,
x﹣1=2,
x﹣1+1=2+1,
x=3,
x=3,
x=18;
(41)x﹣x=14,
x=14,
x=14,
x=18;
(42)3x﹣x=,
x=,
x=,
x=;
(43)=,
=72×,
=,
÷=÷,
x=;
(44):=,
x=×5,
x=6,
x=6,
x=9;
(45)=:,
x=18×,
x=,
x=,
x=12;
(46):=x:,
x=×,
x=,
x=;
(47)x=+1,
x×=×,
x=1
(48) 1﹣25%X+25%x=+25%x,
+﹣=1﹣,
=,
x=3;
=,
(49)
=×,
÷=×÷,
x=8;
×X=,
(50)
×X÷=,
x=;
(51)
5:8=x:32,
8x=5×32,
8x÷8=5×32÷8,
x=20
(52)2x+3×=,
2x+=,
2x+﹣=﹣,
2x÷2=÷2,
x=;
(53)﹣=,
=,
÷=÷,
x=;
(54)×(7﹣)=,
×(7﹣)=,
7﹣=,
7﹣+=+,
7﹣=+﹣,
÷=÷,
x=;
(55)x:=:,
x=×,
x=,
x=
(56) 150%x+66=99
+66=99
=33
x=22
(57)x+6﹣=16
+6=16
=10
x=50
(58)
x=
(59)
=
x=10
(60)3÷(X﹣)=
3÷(X﹣)×(x﹣)=×(x﹣),
3=﹣,
3+=﹣+,
=,
÷=÷,
x=;
(61)(X+):2=(X﹣4):,
×(x﹣4)=(x+)×,
x﹣×4=x+×,
x﹣10﹣x=x+x,
﹣10+10=+10,
÷=÷,
x=
(62) X÷=,
X÷×=×,
X=;
(63)2X﹣4×6=80,
2X﹣24=80,
2X﹣24+24=80+24,
2X=104,
2X÷2=104÷2,
X=52;
(64)4×﹣3X=,
18﹣3X=,
18﹣3X+3X=+3X,
+3X=18,
+3X﹣=18﹣,
3X=,
3X÷3=÷3,
X=;
(65)4X﹣=10,
4X﹣+=10+,
4X=,
4X÷4=÷4,
X=;
(66)+X=20,
=20,
÷=20÷,
X=;
(67)×12+15X=,
+15X=,
+15X﹣=﹣,
15X=42,
15X÷15=42÷15,
X=
(68)6X+5=17,
6x+5﹣5=17﹣5,
6x÷6=12÷6,
x=2;
(69)×(+X)=,
×(+X)÷=÷,
+x=7,
+x﹣=7﹣,
x=;
(70):=X:,
x=×,
x÷=,
x=
(71),
,
,
;
(72)
,
,
,
,
;
(73),
,
,
(74)4(+x)=,
+4x=,
+4x﹣=﹣,
4x=4,
x=1;
(75)×+x=,
+x=,
+x﹣=﹣,
x=,
x=
(76)x﹣,
,
,
x=;
(77)200:6=x:,
6x=200×,
6x÷6=480÷6,
x=80
(78)4÷X=,
4÷X×X=X,
X=4,
X÷=4÷,
X=10;
(79)8(x﹣2)=2(x+7),
8X﹣16=2X+14,
6X﹣16=14,
6X=30,
X=5;
(80):18%=,
X=×,
X=,
X=
﹣2x=,
(81)
﹣2x+2x=+2x,
+2x=,
+2x﹣=﹣,
2x=,
2x÷2=÷2,
x=;
x+x=46,
(82)
x(+)=46,
x=46,
x÷=46÷,
x=40;
(83):x=:,
x=×,
x=,
x÷=÷,
x=;
(84)=,
=×2,
=,
÷=÷,
x=8
(85)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,
3x÷3=13÷3,
x=;
(86)=,
3(6x﹣1)=64,
18x﹣3=64,
18x﹣3+3=64+3,
18x=67,
18x÷18=67÷18,
x=
(87)8(2X﹣7)=5(X+13),
16x﹣56=5x+65,
16x﹣56﹣5x=5x+65﹣5x,
11x﹣56=65,
11x﹣56+56=65+56,
11x=121,
11x÷11=121÷11,
x=11,
(88)3(x+)=60,
3(x+)÷3=60÷3,
x+=20,
x+﹣=20﹣,
x=
(89)+=,
+﹣=﹣,
=,
÷=÷,
x=;
(90)3(x﹣)=,
3x﹣=,
3x﹣+=+,
3x=,
3x÷3=÷3,
x=;
(91)﹣5x=,
﹣5x+5x=+5x,
+5x=,
+5x﹣=﹣,
5x=,
5x÷5=÷5,
x=
(92) x:=
25x=×
3,
25x=,
25x÷25=,
x=;
(93)+2x=,
+2x=,
2x=0,
x=0;
(94)x=15%,
x×x=15%x,
=,
÷=÷,
x=1;
(95)x﹣x=,
x=,
x=,
x=.
(96)x+50%x=6,
=6,
÷=6÷,
x=4;
(97):x=:12,
=,
÷=9÷,
x=30;
(98)4x+2(8﹣x)=26,
4x+16﹣2x=26,
2x+16=26,
2x+16﹣16=26﹣16,
2x÷2=10÷2,
x=5
(99)x﹣=0,
x﹣+=0+,
x=,
x×3=×3,
x=;
(100)+x=1,
+x﹣=1﹣,
x=,
x×=×,
x=1;
(101)x×(+)=,
x=,
x×=×,
x=.
(102),
,
,
3x÷3=,
x=;
(103),
,
,
x=20;
(104)x﹣,
,
,
x=;
(105)x×,
x×,
x=
(106)5x+35=650,
5x+35﹣35=650﹣35,
5x=615,
5x÷5=615÷5,
x=123;
(107)720÷3x=80,
720÷3x×3x=80×3x,
240x=720,
240x÷240=720÷240,
x=3;
(108)﹣=,
(﹣)x=,
=,
÷=÷,
x=3;
(109)4×﹣3x=6,
18﹣3x=6,
18﹣3x+3x=6+3x,
6+3x=18,
6+3x﹣6=18﹣6,
3x=12,
3x÷3=12÷3,
x=4
(110)=,
=10×,
÷=8÷,
x=;
(111)6×3﹣=,
18﹣=,
18﹣+=+,
+=18,
+﹣=18﹣,
=,
÷=÷,
X=6
(112)÷x=,
x=÷,
x=;
(113)x÷=42,
x=42×,
x=9;
(114)x+=,
x+﹣=﹣,
x=,
x÷=÷,
x=
(115)7x÷3=,
7x÷3×3=×3,
7x=,
7x÷7=÷7,
x=;
(116)12:=x:,
=12×,
=6,
÷=6÷,
x=10;
(117)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
(118)3x﹣70%x=,
3x﹣=,
=,
÷=÷,
x=4;
(119)
6+x=240,
6+x﹣6=240﹣6,
x=234,
x÷=234÷,
x=390
(120)﹣=,
﹣+=+,
+=,
+﹣=﹣,
÷=10÷,
x=25;
(121)x:=4:2,
2x=×4,
2x÷2=14÷2,
x=6
(122)x﹣﹣6=16,
﹣6=16,
﹣6+6=16+6,
÷=22÷,
x=110;
(123):=x:8,
x=8×,
x×=8××,
x=4;
(124),
=2×,
÷=÷,
x=;
(125)x:15=:,
x=15×,
x×6=15××6,
x=40;
(126)x+x=,
x=,
x×=×,
x=;
(127)x×50%﹣x=5,
x=5,
x×6=5×6,
x=30;
(128)1﹣x=,
1﹣x+x=+x,
+x=1,
+x﹣=1﹣,
x×=×,
x=;
(129)+1x=3,
+1x﹣=3﹣,
x=,
x×=×,
x=
(130)3x﹣2=4,
3x﹣2+2=4+2,
3x=6,
3x÷3=6÷3,
x=;
(131)﹣3x=2,
﹣3x+3x=2+3x,
3x+2=,
3x+2﹣2=﹣2,
3x=6,
3x÷3=6÷3,
x=2;
(132)3÷x=4,
3÷x×x=4×x,
4x=3,
4x÷4=3÷4,
x=
(133)x﹣5%=,
解:x﹣5%+5%=+5%,
x=,
x=23;
(134):=:(4﹣x),
解:4x=,
2﹣x+x=x,
2﹣+x,
=x,
x=3
(135) 6x+31=49,
6x+31﹣31=49﹣31,
6x=18,
6x÷6=18÷6,
x=3;
(136) 7x÷3=,
7x÷3×3=×3,
7x=,
7x÷7=÷7,
x=;
(137)
﹣9x=,
﹣9x+9x=+9x,
+9x=,
+9x﹣=﹣,
9x=,
9x÷9=÷9,
x=;
(138) x﹣=16,
(1﹣)x=16,
=16,
÷=16÷,
x=25;
(139)
6×7+3x=69,
42+3x=69,
42+3x﹣42=69﹣42,
3x=27,
3x÷3=27÷3,
x=9;
(140)
6x+2x﹣56=0,
(6+2)x﹣56+56=0+56,
8x=56,
8x÷8=56÷8,
x=7
(141) 3x﹣×4=,
3x﹣=,
3x﹣+=+,
3x=,
3x÷3=÷3,
x=;
(142) ﹣=,
=,
÷=÷,
x=;
(143) ÷(9﹣x)=3,
9﹣x=÷3,
9﹣x=,
x=9﹣,
x=;
(144) 3x÷=8,
3x÷×=8×,
3x=,
3x÷3=÷3,
x=
(145)5x+28=71,
5x+28﹣28=71﹣28,
5x=43,
5x÷5=43÷5,
x=;
(146)﹣=,
﹣+﹣=+﹣,
=,
=,
÷=÷,
x=4;
(147)8x﹣=,
=,
÷=÷,
x=7;
(148)﹣×4=,
﹣=,
﹣+=+,
=,
÷=÷,
x=,;
(149)54÷2+3x=72,
27+3x=72,
27+3x﹣27=72﹣27,
3x=45,
3x÷3=45÷3,
x=15;
(150)8x﹣=,
8x﹣+=+,
8x=,
8x÷8=÷8,
x=
(151)x÷=,
x÷×=×,
x=,
x×4=×4,
x=;
(152)x+30%x=26,
(1+30%)x=26,
=26,
÷=26÷,
x=20;
(153) ﹣3x=,
﹣3x+3x=+3x,
+3x=,
+3x﹣=﹣,
3x=,
3x÷3=÷3,
x=
(154) 6×3﹣=,
18﹣=,
18﹣+=+,
18=+,
18﹣=+﹣,
=,
÷=÷,
x=6;
(155)10:x=:,
=10×,
=8,
÷=8÷,
x=;
(156):=x:,
x=×,
x=,
x÷=÷,
x=
(157)X﹣=,
X﹣+=+,
X=;
(158)﹣X=,
﹣X+X=+X,
X+=,
X+﹣=﹣,
X=20;
(159)X﹣(+)=,
X﹣=,
X﹣+=+,
X=
(160)÷x=,
÷x×x=×x,
x=,
x÷=÷,
x=×,
x=;
(161)=,
+=+,
=20,
×8=20×8,
x=160
(162)x﹣80%x=48,
(1﹣)x=48,
=48,
÷=48÷,
x=240;
(163)75%x﹣5×=6,
﹣3=6,
﹣3+3=6+3,
=9,
÷=9÷,
x=12
(164)x﹣=,
x﹣+=+,
x=;
(165)=,
÷=÷,
x=3;
(166)﹣y=,
=,
÷=÷,
y=;
(167)5x+=,
5x+﹣=﹣,
5x=5,
5x÷5=5÷5,
x=1
(168)
x﹣=,
x﹣+=﹣,
x=;
(169)
9x+5x=,
14x=,
14x÷14=÷14,
x=;
(170) +=,
﹣+=﹣,
=8,
÷=8÷,
x=
(171)5÷x=,
5÷x×x=x,
5=x,
5÷=x÷,
x=;
(172)﹣x=,
﹣x+x=+x,
=+x,
﹣=+x﹣,
=x,
÷==x÷,
x=1;
(173)×﹣3x=,
﹣=,
﹣+=+,
=+,
﹣=+﹣,
0=,
0÷=÷,
x=0
(174)(1+25%)x=,
=,
÷=÷,
x=;
(175)x﹣40%x=9,
=9,
÷=9÷,
x=15;
(176)x×20%=,
x×20%÷20%=÷20%,
x=76
(177)30x﹣30=180,
30x﹣30+30=180+30,
30x=210,
30x÷30=210÷30,
x=7;
(178)x﹣x=,
x=,
x÷=÷,
x=;
(179)x÷75%=3,
x÷75%×75%=3×75%,
x=,
x÷=÷,
x=
(180)4x﹣,
4x﹣6=,
4x=+6,
x=÷4,
x=.
(181):x=:,
x=×,
x=2,
x=2×,
x=5
(182)(x﹣)×6=,
6x﹣×6=,
6x﹣27=,
6x﹣27+27=+27,
6x=,
6x÷6=÷6,
x=6;
(183)27﹣17x=,
27﹣17x+17x=+17x,
+17x=27,
+17x﹣=27﹣,
17x=,
17x÷17=÷17,
x=;
(184)+3x=×5,
+3x﹣=﹣,
3x=,
3x÷3=÷3,
x=
(185)2x+5=5x﹣7,
2x+5﹣2x=5x﹣7﹣2x,
3x﹣7=5,
3x﹣7+7=5+7,
3x=12,
3x÷3=12÷3,
x=4;
(186) 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÷8=18÷8,
x=;
(187)4x﹣3(20﹣x)+4=0,
7x﹣56=0,
7x﹣56+56=0+56,
7x=56,
7x÷7=56÷7,
x=8;
(188)﹣=1,
(﹣)×24=1×24,
6(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÷2=6÷2,
y=3
(189)4x﹣5×6=12,
4x﹣30=12,
4x﹣30+30=12+30,
4x=42,
4x÷4=42÷4,
x=;
(190)8x﹣3x=,
5x=,
5x÷5=÷5,
x=;
(191)30×(x÷4)=60,
30×(x÷4)÷30=60÷30,
x÷4=2,
x÷4×4=2×4,
x=8;
(192)×﹣3x=,
﹣3x=,
﹣3x+3x=+3x,
3x+=,
3x+﹣=﹣,
3x=,
3x÷3=÷3,
x=
(193)5x﹣×5=8,
5x﹣12+12=8+12,
5x=20,
5x÷5=20÷5,
x=4,
(194)+x=×2,
x=,
x×=×,
x=.
(195)5x+×15=66,
5x+36=66,
5x+36-36=66-36,
5x=30,
5x÷5=30÷5,
x=6;
(196)+=1,
5x=1,
5x÷5=1÷5,
x=;
(197)×16-8x=12,
40-8x=12,
40-8x+8x=12+8x,
8x+12=40,
8x+12-12=40-12,
8x=28,
8x÷8=28÷8,
x=.
(198)=,
+3x=+3x,
+3x=,
+=,
3x=,
3x÷3=÷3,
x=;
(199)5(x+6)=75,
5x+30=75,
5x+30-30=75-30,
5x=45,
5x÷5=45÷5,
x=9;
(200)x÷+×3=4,
x÷+=4,
x÷+,
x÷=,
x÷×=×,
x=.