(3a^2+2a-8)^2-(a^2-2a-8)^2=多少,

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(3a^2+2a-8)^2-(a^2-2a-8)^2=多少,(3a^2+2a-8)^2-(a^2-2a-8)^2=多少,(3a^2+2a-8)^2-(a^2-2a-8)^2=多少,用平方差公式:(3a

(3a^2+2a-8)^2-(a^2-2a-8)^2=多少,
(3a^2+2a-8)^2-(a^2-2a-8)^2=多少,

(3a^2+2a-8)^2-(a^2-2a-8)^2=多少,
用平方差公式:
(3a²+2a-8)²-(a²-2a-8)²
=[(a+2)(3a-4)]²-[(a+2)(a-4)]²
=(a+2)²[(3a-4)²-(a-4)²]
=(a+2)²[(3a-4)+(a-4)][(3a-4)-(a-4)]
=(a+2)²(4a-8)(2a)
=8a(a+2)²(a-2)