Помогите решить 7 класс

Решите задачу:

$\left \{ {{\frac{1}{x}+\frac{1}{y}=\frac{1}{4}} \atop {\frac{x}{2}=4+\frac{3y}{4}=\frac{16+3y}{4}}} \right. \; \left \{ {{\frac{2}{16+3y}+\frac{1}{y}=\frac{1}{4}} \atop {x=\frac{16+3y}{2}}} \right. \; x\ne0,y\ne0\\\\\frac{2y+16+3y}{y(16+3y)}=\frac{1}{4}\\\\4(16+5y)=y(16+3y)\\\\64+20y=16y+3y^2\\\\3y^2-4y-64=0\\\\\frac{D}{4}=4+192=196,\\\\y_1=\frac{2-14}{3}=-4,\; y_2=\frac{16}{3} \\\\x_1=\frac{16-12}{2}=2,\; x_2=\frac{16+16}{2}=16\\\\Otvet:\; (2,-4),\; (16,\frac{16}{3})$