x4+x3y+x2y2+xy3+y4. x4−x3y+x2y2−xy3+y4. x5+x4y+x3y2+x2y3+xy4+y5. x5−x4y+x3y2−x2y3+xy4−y5. [2]Exercise31. 2x(x−2). 3a(a2−2). 5a2b2(1−2ab). xy(3x+4y). 4a2b2(2a+b). 3a2(a2−4−2a). 4x2(1−2x2−3x3). 5(1−2x2y2+3x2y). 7a(a+2−3a2). 3x2y2(xy−2x2y2−3). Exercise32. (x2+1)(x+1). (x2+1)(x−1). (x+y)(x+z). (x−y)(a−b). (a+b)(a−c). (x+3)(x−b). (x2+2)(2x−1). (a−b)(a−3). (2a−c)(3a+b). (xy+c)(ab+c).