(3a-2b)²-(3a+2b)=-48为什么等于(3a-2b-3a-2b)(3a-2b+3a+2b)=-48用平方差公式怎么得来的?
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![(3a-2b)²-(3a+2b)=-48为什么等于(3a-2b-3a-2b)(3a-2b+3a+2b)=-48用平方差公式怎么得来的?](/uploads/image/z/385483-67-3.jpg?t=%283a-2b%29%26%23178%3B-%283a%2B2b%29%3D-48%E4%B8%BA%E4%BB%80%E4%B9%88%E7%AD%89%E4%BA%8E%283a-2b-3a-2b%29%283a-2b%2B3a%2B2b%29%3D-48%E7%94%A8%E5%B9%B3%E6%96%B9%E5%B7%AE%E5%85%AC%E5%BC%8F%E6%80%8E%E4%B9%88%E5%BE%97%E6%9D%A5%E7%9A%84%3F)
(3a-2b)²-(3a+2b)=-48为什么等于(3a-2b-3a-2b)(3a-2b+3a+2b)=-48用平方差公式怎么得来的?
(3a-2b)²-(3a+2b)=-48为什么等于(3a-2b-3a-2b)(3a-2b+3a+2b)=-48用平方差公式怎么得来的?
(3a-2b)²-(3a+2b)=-48为什么等于(3a-2b-3a-2b)(3a-2b+3a+2b)=-48用平方差公式怎么得来的?
是(3a-2b)^2 - (3a+2b)^2 = -48吧,
u = 3a-2b,v=3a+2b,
-48=u^2-v^2=(u-v)(u+v)=[3a-2b-(3a+2b)][3a-2b+3a+2b)=(3a-2b-3a-2b)(3a-2b+3a+2b)