x+y4x−y3. ab7−3d3c−abd. 1+1x+11−1x−1. 2m+xm+x−11−xm+x. x+yx2−y2x−yx+y. a+aba−ba−aba+b. 9a2−64a−1−a+44. 1x+1y1x−1y. x+3+2x1+3x+2x2. 1x−2x2+1x3(1−x)2x2. x2−x−61−4x2.