a) 4+ (-2+5 - 4)-(4-5) + 5 =
b)(+4).(-5):(-2): (+5)=
c) 8+3.2 - (1 + 4:2) =
d) (-3)×(-4)÷(+6)=
e) 1+3×(-2)+(-1-4)=
f)1+7×(8-5)-12÷2×3=
​