(3x+2)^2-(2x-3)^2

问题描述:

(3x+2)^2-(2x-3)^2

原式=(3x+2)(3x+2)-(2x-3)(2x-3)
=9x^2+12x+4-[4x^2-12x+9]
=9x^2+12x+4-4x^2+12x-9
=5x^2+24-5