Maximize −4x + 5y + 70 subject to the constraints: 2x + y ≤ 8
x + 3y ≥ 5
x + y ≤ 6
x ≥ 0,
y ≥ 0

a. Fix any constraints, as needed, and then convert the linear programming problem into a system of linear equations.
b. Give a fully labeled initial tableau, and circle the pivot element.