化简求值 2m-(-3n+(4n-2(3m-n)+5n))其中m=-(1/2) n=-1已知A=3a^2-2a+1,B=5a^2-3a+2,求3A-2B

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化简求值 2m-(-3n+(4n-2(3m-n)+5n))其中m=-(1/2) n=-1已知A=3a^2-2a+1,B=5a^2-3a+2,求3A-2B
化简求值 2m-(-3n+(4n-2(3m-n)+5n))其中m=-(1/2) n=-1
已知A=3a^2-2a+1,B=5a^2-3a+2,求3A-2B

化简求值 2m-(-3n+(4n-2(3m-n)+5n))其中m=-(1/2) n=-1已知A=3a^2-2a+1,B=5a^2-3a+2,求3A-2B
2m-(-3n+(4n-2(3m-n)+5n))
= 2m-(-3n+(4n-6m-2n+5n))
=2m-(-3n+4n-6m-2n+5n)
=2m+3n-4n+6m+2n-5n
=(2+6)m+(3-4+2-5)n
=8m-4n
=8x(-1/2)-4x(-1)
=-4+4
=0

2m-(-3n+(4n-2(3m-n)+5n))
=2m+3n-(4n-2(3m-n)+5n)
=2m+3n-4n+2(3m-n)-5n
=2m+3n-4n+6m-2n-5n
=8m-8n
=-8-16
=-24