已知|a+b+5|+(a+2)2=0,求3a2b-[2a2b-(3ab-a2b)-4a2]-2ab的值.
问题描述:
已知|a+b+5|+(a+2)2=0,求3a2b-[2a2b-(3ab-a2b)-4a2]-2ab的值.
答
∵|a+b+5|+(a+2)2=0,∴a+b+5=0,a+2=0,解得:a=-2,b=-3,∴3a2b-[2a2b-(3ab-a2b)-4a2]-2ab=3a2b-[2a2b-3ab+a2b-4a2]-2ab=3a2b-2a2b+3ab-a2b+4a2-2ab=ab+4a2=(-2)×(-3)+4×(-2)2=6+16=22....