1/2abc - (4ab+2abc)+(-bc+5ab) dla a = -2 ; b= 1/2 c= -4 . Powinno wyjść : -5 . ;)

1/2abc - (4ab+2abc)+(-bc+5ab) = ½abc-4ab-2abc-cb+5ab = -1,5abc+ab-cb = -1,5*(-2)*½*(-4)+(-2)*½-(-4)*½ = -6-1+2 = -5