$\frac{6y + 7}{4} + \frac{8 - 5y}{3} = 5$ |*12
3(6y + 7) + 4(8 − 5y) = 60
18y + 21 + 32 − 20y = 60
−2y = 60 − 53
−2y = 7
y = 7 : (−2)
y = −3,5

$\frac{5a - 1}{3} = \frac{2a - 3}{5} - 1$ |*15
5(5a − 1) = 3(2a − 3) − 15
25a − 5 = 6a − 9 − 15
25a − 6a = −24 + 5
19a = −19
a = −19 : 19
a = −1

$\frac{11x - 4}{7} - \frac{x - 9}{2} = 5$ |*14
2(11x − 4) − 7(x − 9) = 70
22x − 8 − 7x + 63 = 70
15x = 70 − 55
15x = 15
x = 15 : 15
x = 1

$\frac{2c - 1}{9} + \frac{c}{4} = \frac{c + 3}{6}$ |*36
4(2c − 1) + 9c = 6(c + 3)
8c − 4 + 9c = 6c + 18
17c − 6c = 18 + 4
11c = 22
c = 22 : 11
c = 2

$\frac{3p - 1}{24} - \frac{2p + 6}{36} - 1 = 0$ |*72
3(3p − 1) − 2(2p + 6) − 72 = 0
9p − 3 − 4p − 12 − 72 = 0
5p = 87
p = 87 : 5
p = 17,4

$5 - \frac{1 - 2x}{4} = \frac{3x + 20}{6} + \frac{x}{3}$ |*12
60 − 3(1 − 2x) = 2(3x + 20) + 4x
60 − 3 + 6x = 6x + 40 + 4x
6x − 6x − 4x = 40 − 57
−4x = −17
$x = \frac{17}{4} = 4\frac{1}{4}$
x = 4,25