$$11) 25x^{2}=5x+6$$
$$12) 12x^{2}-11ax=36a^{2}$$
$$13) 35b^{2}=9x^{2}+6bx$$
$$14) x^{2}-2ax+4ab=2bx$$
$$15) 3x^{2}-2ax-bx=0$$
$$16) \frac{23}{x+4}+\frac{3x}{11}=\frac{1}{3}(x+5) $$
$$17) \frac{3x-4}{x+1}-\frac{x-1}{3x+4}+\frac{1}{2}=0$$
$$18) x^{2}+2cx-2dx=2cd-d^{2}$$
$$19) \frac{1}{a+x}+\frac{1}{b+x}=\frac{a+b}{bx}$$
$$20) \frac{x+m}{x-m}+\frac{x-m}{x+m}=\frac{x^{2}+m^{2}}{x^{2}-m^{2}}+\frac{x^{2}-m^{2}}{x^{2}+m^{2}}$$