a: 7x+58=100
nên 7x=42
hay x=6
c: x-56:x=16
nên x-14=16
hay x=30
c)x - 56 : 4 = 16
x - 56 = 16 : 4
x- 56 = 4
x =4 + 56
x = 60
d)101 + (36 - 4x) = 105
(36- 4x ) = 105 - 101
36 - 4x = 4
4x = 36 - 4
4x = 32
x = 32:4
x = 8
a) 58 + 7x = 100
7x = 100 - 58
7x = 42
x = 42 : 7
x = 6
b) (x - 12) : 12 = 12
x - 12 = 12 . 12
x - 12 = 144
x = 144 + 12
x = 156
g) 2x - 49 = 5.32
2x - 49 = 160
2x = 160 + 49
2x = 209
x = 209 : 2
x = 104,5
h) [(8x - 12) : 4].33 = 36
(8x - 12) : 4 = 36 : 33
8x - 12 = \(\dfrac{12}{11}\) . 4
8x = \(\dfrac{48}{11}\) + 12
8x = \(\dfrac{48}{11}+\dfrac{132}{11}\)
x = \(\dfrac{180}{11}\) : 8
x = \(\dfrac{180}{11}\) . \(\dfrac{1}{8}\)
x = \(\dfrac{45}{22}\)
e)2. (x-51)= 2.23 + 20
2.(x-51)= 46 + 20
2.(x-51) = 66
x- 51 = 66 :2
x - 51 = 33
x = 33 + 51
x = 84
f, 10- (x-3) : 2 = 72 - 110
10 - (x-3) : 2 = -38
10 - (x-3) :2 = -38
( x-3) :2 = 10 - (-38)
(x-3): 2 = 48
x-3 = 48 x 2
x-3 = 96
x = 96+3
x = 99
i) 52x - 3 - 2 . 52 = 52 . 3
52x - 3 - 104 = 156
52x = 156 + 104 + 3
x = 263 : 52
x = \(\dfrac{263}{52}\)
k) (3x - 7) : 4 = 5
3x - 7 = 5 . 4
3x = 20 + 7
x = 27 : 3
x = 9