(2A-B)(2A+B)-2(3A-2B)(-2B-3A)先化解再求值(X+2)(X-2)-X(X-1)其中X=-1

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(2A-B)(2A+B)-2(3A-2B)(-2B-3A)先化解再求值(X+2)(X-2)-X(X-1)其中X=-1
(2A-B)(2A+B)-2(3A-2B)(-2B-3A)
先化解再求值(X+2)(X-2)-X(X-1)其中X=-1

(2A-B)(2A+B)-2(3A-2B)(-2B-3A)先化解再求值(X+2)(X-2)-X(X-1)其中X=-1
(2A-B)(2A+B)-2(3A-2B)(-2B-3A)
=(2a+b)(2a-b)-2(-2b+3a)(-2b-3a)
=(4a^2-b^2)-2(4b^2-9a^2)
=4a^2-b^2-8b^2+18a^2
=22a^2-9b^2
(X+2)(X-2)-X(X-1)
=x^2-4-x^2+x
=x-4
=-1-4
=-5