Question

64.3 - 3 x 2 by the power of 3 divided by two

Answer 1

If you meant:

64.3-3*(2³)/2

That would be 52.3 :)

Answer 2

64.3-3*(2³)/2=52.3
64.3-3*8/2
64.3-24/2
64.3-12
52.3