(要过程)已知3a-5b+19=0,a+8b-1=0,求:(1)-12a-9b (2)4a-26b (3)(4a+3b)×(4a+3b)-8a-6b

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(要过程)已知3a-5b+19=0,a+8b-1=0,求:(1)-12a-9b (2)4a-26b (3)(4a+3b)×(4a+3b)-8a-6b

(要过程)已知3a-5b+19=0,a+8b-1=0,求:(1)-12a-9b (2)4a-26b (3)(4a+3b)×(4a+3b)-8a-6b
(要过程)已知3a-5b+19=0,a+8b-1=0,求:(1)-12a-9b (2)4a-26b (3)(4a+3b)×(4a+3b)-8a-6b

(要过程)已知3a-5b+19=0,a+8b-1=0,求:(1)-12a-9b (2)4a-26b (3)(4a+3b)×(4a+3b)-8a-6b
3a-5b = -19------1式
a+8b = 1-------2式
-(a+8b)*3-(3a-5b)*3 = -12a-9b= 54
(3a-5b)*2-(a+8b)*2= 4a-26b= -40
4a+3b= 1式+2式= -18
问3 = (4a+3b)^2- 2(4a+3b)
= -20(4a+3b) = 360

第二个式子用b表示出a然后代到第一个式子得b的表达式,算出b在算a就行了