Algebra-1

A farmer has 100 acres of land and wants to plant corn and wheat. Each acre of corn requires 2 hours of labor, and each acre of wheat requires 1 hour of labor. The farmer can work a maximum of 150 hours per week. Additionally, the farmer wants to plant at least 20 acres of corn. Let  be the number of acres of corn and  be the number of acres of wheat (are non-negative integers). Write the system of inequalities that represents this situation.  _________.