一:(4a+3a²-3)-(-a+4a²)+a².
=4a+3a²-3+a-4a²+a²
=4a+a+3a²-4a²+a²-3
=(4+1)a+(3-4+1)a²-3
=5a-3
解当a=-2时,
5a-3
=5x(-2)-3
=(-10)-3
=-13
一:(4a+3a²-3)-(-a+4a²)+a².
=4a+3a²-3+a-4a²+a²
=4a+a+3a²-4a²+a²-3
=(4+1)a+(3-4+1)a²-3
=5a-3
解当a=-2时,
5a-3
=5x(-2)-3
=(-10)-3
=-13