Question

СРОЧНО СРОЧНО СРОЧНО​

Answer 1

$\dfrac{3}{10x-4y}-\dfrac{5x-8y}{4y^{2}-25x^{2}}+\dfrac{3}{10x+4y}= \\\\\\=\dfrac{3}{2(5x-2y)}+\dfrac{5x-8y}{(5x-2y)(5x+2y)}+\dfrac{3}{2(5x+2y)}= \\\\\\=\dfrac{3(5x+2y)+2(5x-8y)+3(5x-2y)}{2(5x-2y)(5x+2y)}=\dfrac{15x+6y+10x-16y+15x-6y}{2(5x-2y)(5x+2y)}=\\\\\\=\dfrac{40x-16y}{2(5x-2y)(5x+2y)}=\dfrac{8(5x-2y)}{2(5x-2y)(5x+2y)} =\boxed{\dfrac{4}{5x+2y} }$