已知3a-5b+19=0,a+8b-1=0.求下列各式的值:1:-12a-9b 2:4a-26b

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已知3a-5b+19=0,a+8b-1=0.求下列各式的值:1:-12a-9b 2:4a-26b
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已知3a-5b+19=0,a+8b-1=0.求下列各式的值:1:-12a-9b 2:4a-26b
已知3a-5b+19=0,a+8b-1=0.求下列各式的值:
1:-12a-9b 2:4a-26b

已知3a-5b+19=0,a+8b-1=0.求下列各式的值:1:-12a-9b 2:4a-26b
小状元AAA :
3a-5b+19=0,3a-5b=-19 ①
a+8b-1=0,即a+8b=1 ②
①+②,得
4a+3b=-18
①-②,得
2a-13b=-20
1、-12a-9b
=-3(4a+3b)
=-3×(-18)
=54
2、4a-26b
=2(2a-13b)
=2×(-20)
=-40

3a-5b+19=0 ,a+8b-1=0
两式相加得:4a+3b+18=0
4a+3b=-18
-12a-9b =-3*(4a+3b)=54
两式相减得2a-13b+20=0
2a-13b=-20
4a-26b=2(2a-13)=-40