7. Rezolvati ecuatiile:
a) (2x + 1) + (3x + 6) = 42;
b) (x + 4) + (3x + 8) = 24;
c) (5x + 3) + (2x + 1) + (x + 6) = 90;
d) (x + (x + 7)].5 -105;
e) 2. (3x + 4 . (x + 5)] - 4 = 78.​