化简求值m^2(m+4)+2m(m^2 -1)-3m^3,其中m=2/5
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化简求值m^2(m+4)+2m(m^2 -1)-3m^3,其中m=2/5
m^2(m+4)+2m(m^2 -1)-3m^3
=m³+4m²+2m³-2m-3m³
=4m²-2m
=4×4/25-4/5
=-4/25
化简求值m^2(m+4)+2m(m^2 -1)-3m^3,其中m=2/5
m^2(m+4)+2m(m^2 -1)-3m^3
=m³+4m²+2m³-2m-3m³
=4m²-2m
=4×4/25-4/5
=-4/25