Решите плиз N375 (2,3,4)

Решите задачу:

$\frac{2b}{3+2b}+\frac{5}{3-2b}- \frac{4b^2+9}{4b^2-9}= \frac{2b(3-2b)+5(3+2b)-4b^2-9}{4b^2-9}= \frac{6b-4b^2+15+10b-4b^2+9}{4b^2-9}=\\= \frac{-8b^2+16b+24}{4b^2-9}= \frac{-8(x+1)(x-1)}{4b^2-9}= \frac{8-8x^2}{4b^2-9}$
$\frac{3}{2x^2+2x}+ \frac{2x-1}{x^2-1}- \frac{2}{x}= \frac{3}{2x(x+1)}+ \frac{2x-1}{(x+1)(x-1)}- \frac{2}{x}=\\=\frac{3(x-1)+2x(2x-1)-2*(2x^2-2)}{2x(x-1)(x+1)}= \frac{3x-3+4x^2-2x-4x^2+4}{2x(x-1)(x+1)}= \frac{x+1}{2x(x-1)(x+1)}=\\= \frac{1}{2x(x-1)}$
$\frac{5y}{(x-5y)(x+5y)}-\frac{5y}{y(x-5y)}= \frac{5y^2-5y(x+5y)}{y(x-5y)(x+5y)}= \frac{5y^2-5yx+25y^2}{y(x-5y)(x+5y)}= \\=\frac{30y^2-5yx}{y(x-5y)(x+5y)}= \frac{-5y(x-6y)}{y(x-5y)(x+5y)}$