已知a=1,b=2,c=3,求整式-8ab-{4a-3[6ab+5(ab+a-b)-7a]-2c}

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已知a=1,b=2,c=3,求整式-8ab-{4a-3[6ab+5(ab+a-b)-7a]-2c}
已知a=1,b=2,c=3,求整式-8ab-{4a-3[6ab+5(ab+a-b)-7a]-2c}

已知a=1,b=2,c=3,求整式-8ab-{4a-3[6ab+5(ab+a-b)-7a]-2c}
原式=-8ab-{4a-3[6ab+5ab+5a-5b-7a]-2c}
=-8ab-{4a-3[11ab-5b-2a]-2c}
=-8ab-{4a-33ab+15b+6a-2c}
=-8ab-{10a-33ab+15b-2c}
=-8ab-10a+33ab-15b+2c
=25ab-10a-15b+2c
=25×2-10-30+6
=16

平均数是200,A是C得百

-8ab-{4a-3[6ab+5(ab+a-b)-7a]-2c}
=-8ab-[4a-3(6ab+5ab+5a-5b-7a)-2c]
=-8ab-[4a-3(11ab-2a-5b)-2c]
=-8ab-(4a-33ab+6a+15b-2c)
=-8ab-(10a-33ab+15b-2c)
=-8ab-10a+33ab-15b+2c
=25ab-10a-15b+2c
=25×1×2 -10×1 -15×2 +2×3
=50-10-30+6
=16

-8ab-{4a-3[6ab+5(ab+a-b)-7a]-2c}
=-8ab-4a+18ab+15ab+15a-15b-21a+2c
=25ab-10a-15b+2c
=25*1*2-10*1-15*2+2*3
=16