解
3a³+2a-0.75a³+0.5a-0.6a³-1/3a
=(3a³-0.75a³-0.6a³)+(2a+0.5a-1/3a)
=1.65a³+(2.5a-1/3a)
=1.65a³+(5/2a-1/3a)
=1.65×12³+13/6a
=2851.2+26
2877.2