a) -(2x - 1) = 4 <=>-2x + 1 - 4 = 0 <=> -2x - 3 = 0 <=> x = -3/2
b) 2(x + 1) = x <=> 2x + 2 = x <=> x = -2
c) 2t - (3t + 1) = 6 <=> 2t - 3t - 1 = 6 <=> -t = 7 <=> t = -7
d) -(4 + x) = 2(3 - x) <=> -4 - x = 6 - 2x <=> x = 10
e) 3(y + 6) - y = 2(y + 9) <=> 3y + 18 - y = 2y + 18 <=> 0 = 0 - nieskończenie wiele rozwiązań
f) x - 7 - 2(3x + 5) = 3 <=> x - 7 - 6x - 10 = 3 <=> -5x = 20 <=> x = -4