Notes Factor 4−x2=−(x−2)(x+2)4-x^2=-(x-2)(x+2)4−x2=−(x−2)(x+2). For even expressions, many xxx-numerator terms may become 000 after solving. For repeated quadratic (x2+4)2(x^2+4)^2(x2+4)2, include: Cx+Dx2+4+Ex+F(x2+4)2\frac{Cx+D}{x^2+4}+\frac{Ex+F}{(x^2+4)^2}x2+4Cx+D+(x2+4)2Ex+F