3(2x+1)(2x-1)-4(3x-2)(-3x+2)
=3(4x^2-1)+4(3x-2)^2
=12x^2-3+4(9x^2-12x+4)
=12x^2-3+36x^2-48x+16
=48x^2-48x+13
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满意请采纳
谢谢
3(2x+1)(2x-1)-4(3x-2)(-3x+2)
=3 (4x²-1 ) + 4 (9x²- 12x +4 )
= 12x² - 3 + 36x² - 48x +16
= 48x² -48x +15
(6x+3)(2x-1)-(12x+8)(-3x+2)
没算完,打字搞麻烦