8^4x8^-3×64/8^-1 b.(-3^3)-3/27

a. 8^4 x 8^-2 x 64/8^-1
= 8^4-2x 8^2/8^-1
=8^2+2-(-1)
=8^4+1
=8^5


b. (3^3) ^-3/27
= 3^-9/3^3
= 3^9-3
=3^3