$$1) \frac{1}{x+y}-\frac{1}{x-y}+\frac{2x}{x^{2}-y^{2}}$$
$$2) \frac{1}{2x+y}+\frac{1}{2x-y}-\frac{3x}{4x^{2}-y^{2}}$$
$$3) \frac{5}{1+2x}-\frac{3x}{1-2x}-\frac{4-13x}{1-4x^{2}}$$
$$4) \frac{2a}{2a+3b}+\frac{3b}{2a-3b}-\frac{8b^{2}}{4a^{2}-9b^{2}}$$
$$5) \frac{1}{a+x}+\frac{1}{(a+x)^{2}}-\frac{1}{a^{2}-x^{2}}$$
$$6) \frac{10}{9-a^{2}}-\frac{2}{3+a}-\frac{1}{3-a}$$
$$7) \frac{5x}{6\left(x^{2}-1\right)}-\frac{1}{2(x-1)}+\frac{1}{3(x+1)}$$
$$8) \frac{1}{2(a-b)}-\frac{1}{2(a+b)}-\frac{b}{a^{2}-b^{2}}$$
$$9) \frac{1}{1+x}+\frac{2}{1-x^{2}}+\frac{3}{(1+x)^{2}}$$
$$10) \frac{2a}{2a-3}-\frac{5}{6a+9}-\frac{4(3a+2)}{3(4a^{2}-9)}$$