A)
3x + x / 2 = 4
(6x + x) / 2 = 4
7x / 2 = 4
7x = 2 * 4
7x = 8
x = 8 / 7
b)
5 + 2x / 3 = 4x - 7
2x / 3 - 4x = - 5 - 7
(2x - 12x) / 3 = - 12 - 10x = 3 * - 12 - 10x = - 36
x = - 36 / - 10
x = 18 / 5
c)
2 + 6x = 8 - 4x / 6
6x + 4x / 6 = 8 - 2
(36x + 4x) / 6 = 6
36x + 4x = 6 * 6
40x = 36
x = 36 / 40
x = 9 / 10
d)
(x + 2) / 3 - 1 = (2x - 1) / 4
(x + 2) / 3 - (2x - 1) / 4 = 1
(4(x + 2) - 3(2x - 1)) / 12 = 1
(4x + 8 - 6x + 3) / 12 = 1 - 2x + 11 = 12 * 1 - 2x = 12 - 11 - 2x = 1
x = - 1 / 2
e)
(4X - 1) / 6 + 2 = (3X - 1) / 8
(4x - 1) / 6 - (3x - 1) / 8 = - 2
(4(4x - 1) - 3(3x - 1)) / 24 = - 2
(16x - 4 - 9x + 3) = 24 * - 2
7x - 1 = - 48
7x = - 48 + 1
7x = - 47
x = - 47 / 7
f)
(3X - 2) / 4 + 5 = (X + 3) / 2
(3x - 2) / 4 - (x + 3) / 2 = - 5
((3x - 2) - 2(x + 3)) / 4 = - 5
3x - 2 - 2x - 6 = - 20
x = - 20 + 8
x = - 12
g)
(2(X + 1)) / 3 + 4(X - 2) = X / 2 + 5
(2x + 2) / 3 + 4x - 8 = x / 2 + 5
(2x + 2) / 3 + 4x - x / 2 = 5 + 8
(2(2x + 2) + 24x - 3x) / 6 = 13
4x + 4 + 24x - 3x = 72
25x = 78 - 4
25x = 74
x = 74 / 25
saludos : ).