(1)-2c(b^2-4ac)
=-2c×b²-(-2c)×4ac
=-2b²c+8ac²
(2)ab(3-b)-2a(b-1/2b^2)
=3ab-ab²-2ab+ab²
=ab
(3)4m(2m^2-5m+1）-2m(3m-2)
=8m³-20m²+4m-6m²+4m
=8m³-26m²+8m