0.75+x=3.75, 0.75+x﹣0.75=3.75﹣0.75,
x=3,
x÷=3÷,
x=6;
(28)0.8:
=0.48:x,
0.8x=
×0.48,
0.8x=0.2,
0.8x÷0.8=0.2÷0.8, x= (29)χ﹣χ=,
x=,
x
=
,
x=3;
(30)42:=χ:
x=42×,
x
=30
,
x=50;
(31)5x﹣0.4=75%, 5x﹣0.4+0.4=75%+0.4, 5x÷5=1.15÷5, x=0.23
( 32) 6x﹣0.9=4.5, 6x﹣0.9+0.9=4.5+0.9, 6x=5.4, 6x÷6=5.4÷6, x=0.9;
(33)2(x﹣3)=5.8, 2(x﹣3)÷2=5.8÷2 x﹣3=2.9,
x﹣3+3=2.9+3, x=5.9; (34) 1.6x=6.4, 1.6x÷1.6=6.4÷1.6, 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÷1.1=3, x÷1.1×1.1=3×1.1, x=3.3 (38)+2x=, +2x
=
,
2x=, 2x÷2=÷2, x=;
(39)
×3﹣7x=1.04,
2.16﹣7x=1.04,
2.16﹣7x﹣1.04=1.04﹣1.04, 1.12﹣7x=0,
7x÷7=1.12÷7, x=0.16; (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)
=
,
2.4x=72×0.26, 2.4x=18.72,
2.4x÷2.4=18.72÷2.4, x=7.8; (44)1.2:=, x=1.2×5, x=6, x
=6
,
x=9; (45)
=
:,
x=18×,
x=,
x
=
,
x=12; (46):=x:0.8,x=×0.8, x
=0.04
,
x=0.2; (47)x=+1,
x
×=
×,
x=1
(48) 1﹣25%X+25%x=+25%x, 0.25x+0.25﹣0.25=1﹣0.25, 0.25x=0.75, x=3;
=
,
(49)
0.25x=1.25×1.6,
0.25x÷0.25=1.25×1.6÷0.25, x=8;
×X=
, (50)×X÷=,
x=;
(51) 5:8=x:32, 8x=5×32, 8x÷8=5×32÷8, x=20
(52)2x+3×0.9=24.9, 2x+2.7=24.9,
2x+2.7﹣2.7=24.9﹣2.7, 2x÷2=22.2÷2, x=11.1; (53)5.3x﹣2.9x=,
2.4x=,
2.4x÷2.4=÷2.4,
x=;
(54)×(7﹣2.8x)=1.5, ×(7﹣2.8x)
=1.5
,
7﹣2.8x=2.1,
7﹣2.8x+2.8x=2.1+2.8x,
7﹣2.1=2.1+2.8x﹣2.1, 4.9÷2.8=2.8x÷2.8, x=1.75; (55)x:0.3=:, x=0.3×,
x=, x=
(56)150%x+66=99 1.5x+66=99 1.5x=33 x=22 (57)x+6﹣0.8x=16 0.2x+6=16 0.2x=10 x=50
(58)
x=14.4
(59)
0.55x=5.5 x=10 (60)3÷(X﹣)=1.3
3
÷(X﹣)×(x﹣)=1.3×(x﹣), 3=1.3x﹣0.78,
3
+0.78=1.3x﹣0.78+0.78,
4.68=1.3x,
4.68÷1.3=1.3x÷1.3, x=3.6;
(61)(X+0.5):2=(X﹣4):, ×(x﹣4)=(x+0.5)×, x﹣
×4=x+×0.5,
x﹣10﹣x=x+
x,
2.25x﹣10+10=0.125+10, 2.25x÷2.25=10.125÷2.25, x=4.5 (62) X÷0.05=3.528,
X÷0.05×0.05=3.528×0.05, X=0.1764;
(63)2X﹣4×6=80, 2X﹣24=80,
2X﹣24+24=80+24, 2X=104, 2X÷2=104÷2, X=52;
(64)4×4.5﹣3X=6.38, 18﹣3X=6.38, 18﹣3X+3X=6.38+3X, 6.38+3X=18,
6.38+3X﹣6.38=18﹣6.38, 3X=11.62, 3X÷3=11.62÷3, X=
;
(65)4X﹣7.2=10,
4X﹣7.2+7.2=10+7.2, 4X=17.2, 4X÷4=17.2÷4, X=4.3; (66)11.5X+X=20, 12.5X=20,
12.5X÷12.5=20÷12.5, X=1.6;
(67)3.8×12+15X=87.6, 45.6+15X=87.6,
45.6+15X﹣45.6=87.6﹣45.6, 15X=42, 15X÷15=42÷15, X=2.8 (68)6X+5=17,
6x+5﹣5=17﹣5, 6x÷6=12÷6, x=2;
(69)0.6×(2.5+X)=4.2, 0.6×(2.5+X)÷0.6=4.2÷0.6, 2.5+x=7,
2.5+x﹣2.5=7﹣2.5, x=4.5;
(70):=X:
, x=×
,
x÷=
,
x=0.6
(71)
,
,
,
;
(72)
,
,
, ,
;
(73)
, ,
,
(74)4(+x)=,
+4x=, +4x﹣
=
﹣
,
4x=4, x=1; (75)×0.25+x=, 0.2+x=, 0.2+x﹣0.2=﹣0.2,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=0.18×6.5,
X=1.17,
X=7.8
﹣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)
=
, 1.6x=6.4×2, 1.6x=12.8,
1.6x÷1.6=12.8÷1.6, 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+4.5)=60, 3(x+4.5)÷3=60÷3, x+4.5=20,
x+4.5﹣4.5=20﹣4.5, x=15.5 (89)1.6x+2.4=7.52,
1.6x+2.4﹣2.4=7.52﹣2.4, 1.6x=5.12,
1.6x÷1.6=5.12÷1.6, x=3.2;
(90)3(x﹣0.8)=6.3, 3x﹣2.4=6.3, 3x﹣2.4+2.4=6.3+2.4, 3x=8.7, 3x÷3=8.7÷3, x=2.9;
(91)28.4﹣5x=5.8, 28.4﹣5x+5x=5.8+5x, 5.8+5x=28.4,
5.8+5x﹣5.8=28.4﹣5.8, 5x=22.6, 5x÷5=22.6÷5, x=4.52 (92)x:=
25x=×3,
25x=, 25x÷25=,
x=;