Tính: 1/2xy^2 (x^2 - 6y)

Tính
a.1/2xy^2 (x^2-6y)

b.(x-2)(2x+3)

c.(x+5)(x^2-2x +3)

d.(2x-3)(x^2-2x+5)

e.(x-2y)(x+2y)

f.(2x-1)(4x^2+2x+1)

g.(2x-1)(4x^2-2x+1)x+5)