-2,4-(5,6-(1,75+(-2 1\6+5 1\4)))

-2,4-(5,6-(1,75+(-12/6+51/4)))=-2,4-(5,6-(1,75+(-2+12,75)))=-2,4-(5,6-(1,75+10,75))=-2,4-(5,6-12,5)=-2,4-(-6,9)=-2,4+6,9=4,5.