Question

Graph the system of linear inequalities y+x=600 and x=4y

Answer 1

$\displaystyle \left \{ {{y+x=600 } \atop {x=4y}} \right. \\ \\ y+4y=600 \\ 5y=600 \\ y=600:5 \\ y=120 \\ \\ \\ x=4y \\ x=4\cdot120 \\ x=480$