已知3a-5b+19=0,a+8b-1=0,求(4a+3b)＾2-8a-6b的值

已知3a-5b+19=0,a+8b-1=0,求(4a+3b)＾2-8a-6b的值
已知3a-5b+19=0,a+8b-1=0,求(4a+3b)＾2-8a-6b的值

已知3a-5b+19=0,a+8b-1=0,求(4a+3b)＾2-8a-6b的值
3a-5b+19=0 (1)
a+8b-1=0 (2)
(1)+(2)
4a+3b+18=0
4a+3b=-18
(4a+3b)²-8a-6b
=(4a+3b)²-2(4a+3b)
=(-18)²-2(-18)
=360

3a-5b+19=0,a+8b-1=0两式相加，得4a+3b+18=0，所以4a+3b=-18
(4a+3b)＾2-8a-6=(4a+3b)＾2-2(4a+3b)=(-18)²-2×(-18)=360

两式相加可得4a+3b的值

令3a-5b+19=0为（1）,a+8b-1=0为（2）,
（1）+（2）有4a+3b+18=0，即4a+3b=-18
所以-（8a+6b)=-2（4a+3b）=36
(4a+3b)＾2-8a-6b=（-18）＾2+36=360