Помогите решить Пожалуйста

Решите задачу:

$\left \{ {{ \frac{x}{6}+ \frac{y}{5} =1} \atop {4y+3x=16}} \right. \left \{ {{5x+6y=30} \atop {4y=16-3x}} \right. \left \{ {{5x+6(4-0.75x)=30} \atop {y=4-0.75x}} \right. \left \{ {{5x+24-4.5x=30} \atop {y=4-0.75x}} \right. \left \{ {{0.5x=30-24} \atop {y=4-0.75x}} \right.$ $\left \{ {{0,5x=6} \atop {y=4-0.75x}} \right. \left \{ {{x=12} \atop {y=4-0.75*12}} \right. \left \{ {{x=12} \atop {y=4-9}} \right. \left \{ {{x=12} \atop {y=-5}} \right.$