3x²-(2x²+5x-1)-(3x+1)
=3x²-2x²-5x+1-3x-1
=x²-8x
=10²-8×10
=20
3a²b-[2a²b-（2abc-a²b）-4a²c]-abc
=3a²b-2a²b+（2abc-a²b）+4a²c-abc
=a²b+2abc-a²b+4a²c-abc
=abc+4a²c
=6+16
=22