3a^2b-[2a^2b-(2abc-a^2才)-4a^2c]-2abc
=3a^2b-2a^2b+2abc-a^2c+4a^2c-2abc
=a^2b+3a^2c
=a^2(b+3c) a=0.1,b=70 c=10
=0.01(70+30)
=1
3a^2b-[2a^2b-(2abc-a^2才)-4a^2c]-2abc
=3a^2b-2a^2b+2abc-a^2c+4a^2c-2abc
=a^2b+3a^2c
=a^2(b+3c) a=0.1,b=70 c=10
=0.01(70+30)
=1