当m=-1时,-2m²-[-4m²+(-m²)]等于,数学题···

问题描述:

当m=-1时,-2m²-[-4m²+(-m²)]等于,数学题···

-2m²-[-4m²+(-m²)]
=-2m²+4m²+m²
=-2m²+5m²
=3m²
=3×(-1)²
=3×1
=3