I = (x - 8)² + x² - 64
=(x - 8)(x - 8)+(x - 8)(x + 8)
=(x - 8)((x - 8+x+8)
=(x - 8)2x
J = (3x - 7)² - 25
=(3x - 7+5)((3x - 7-5)
=(3x - 2)(3x - 12)
K = (6x - 8)² - (2x + 3)²
=(6x - 8-2x+3)(6x - 8+2x-3)
=(4x-5)(8x-11)
L = (3x - 7)² - (3x - 7)
=(3x - 7)(3x - 7)-(3x - 7)
=(3x - 7)((3x - 7-1)
=(3x - 7)(3x-8)