(x+7y)(x+12y). (ax−6y)(ax−17y). (x+2y)(x−2y)(x2−5y2). (a2x2−11y2)(a2x2−13y2). (a3b3−11c2)(a3b3−12c2). (a+4bc)(a−24bc). (a+8bc)(a−12bc). (a+6bc)(a−16bc). (a−3bc)(a+32bc). (a+2bc)(a−48bc). (a+bc)(a+48bc). (x+9yz)(x−27yz). (xy+13z)(xy−14z). [2]Ejercicio 39. a(a2−7). ab(3ab−2a2+3b2). (a−b+1)(a−b). (a+b+1)(a+b−1). (a+2b)(a2−2ab+4b2). (x+2y+1)(x−2y). (a−b)(a2+ab+b2+1). (a−3b)(a−3b). (x+1)(x−2). (x+1)(x−3). (x−3)(x+7). (a+2)(a−13).