先简化,再求值.(a-3b)^2+(3a+b)^2-(a+5b)^2+(a-5b)^2.其中a=-8,b=-6
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先简化,再求值.(a-3b)^2+(3a+b)^2-(a+5b)^2+(a-5b)^2.其中a=-8,b=-6
先简化,再求值.(a-3b)^2+(3a+b)^2-(a+5b)^2+(a-5b)^2.其中a=-8,b=-6
先简化,再求值.(a-3b)^2+(3a+b)^2-(a+5b)^2+(a-5b)^2.其中a=-8,b=-6
(a-3b)²+(3a+b)²-(a+5b)²+(a-5b)²
=(a²+9b²-6ab)+(9a²+b²+6ab)-(a²+25b²+10ab)+(a²+25b²-10ab)
=a²+9b²-6ab+9a²+b²+6ab-a²-25b²-10ab+a²+25b²-10ab
=10b²+10a²-20ab
=10(a²-2ab+b²)
=10(a-b)²
a=-8,b=-6时
=10×(-8+6)²
=10×(-2)²
=10×4=40