Explanation:
what, you have no calculator at hand ? at least the computer or smart phone you used to pay this question has one installed.
because this is all that needs to be done : use the given numbers and just calculate the results for every expression.
sigh ...
a.
2²×-3 = 4×-3 = -12
b.
6×(2-4)/-3 = 6×-2/-3 = -2×-2 = 4
c.
(-3)² + 2×4 = 9 + 8 = 17
d.
-(-3)² + 2 + 4 = -9 + 6 = -3
e.
-2×(-3 + 2×4)/-3 = -2×(-3 + 8)/-3 = -2×5/-3 = -10/-3 = 10/3