Question

a) 3(x^3-1)= -27 b) 3(x-1)+2= -4x-1 c) 1/3 x-1=2(1/3 x+1/5)

Answer 1

a)
3(x³-1) = -27
x³-1 = -27/3
x³ = -9+1
x³ = -8
x =³√-8
x = -2

b)
3(x-1)+2 = -4x-1 
3x-3+2 = -4x-1
7x = -1+1
7x = 0
x = 0

c)
1/3 x-1= 2(1/3 x+1/5)
x/3-1 = 2x/3+2/5  (multiplicamos todo por 15
5x-15 = 10x+6
5x = -21
x = -21/5

saludos Ariel