7. Rezolvă ecuațiile:
a) 1-{2-[3-(4-x)]}=5
b) -4,5+2 / 5•[1+3•(2•x-1)]= -3-7/5•x
c) 3•x-1/ 4 - 6•x+1/ 6=1-x/ 24
d) 4/5•(3•x-4)+3•x+2/ 2=1 1/2•(x-3)+4•x+7/ 5