-化简求值2/3a-{1/3-[(3a²-5a+1)]},其中a=3

问题描述:

-化简求值2/3a-{1/3-[(3a²-5a+1)]},其中a=3

2/3a-{1/3-[(3a²-5a+1)]}
=2/3a-{1/3-3a²+5a-1}
=2/3a-1/3+3a²-5a+1
=3a²+2/3a-5a-1/3+1
=3a²-13/3a+2/3
=3*3²-13/3*3+2/3
=27-13+2/3
=14+2/3
=46/3