Solve the following linear equations by using the properties of equality:

(a) 6x – 7 = 3x + 2

(b) 60 – 8x = 3x + 5

(c) 7x + 5 = 4(3x – 8) + 7

(d) 3(2x + 9) = 4(5x – 21) – 1