Sketch the region corresponding to the system of constraints. Then find the minimum and maximum values of

Question:

Sketch the region corresponding to the system of constraints. Then find the minimum and maximum values of the objective function (if possible) and the points where they occur, subject to the constraints.
1. Objective function:
z = 3x + 4y
Constrains:
x ≥ 0
t ≥ 0
2x + 5y ≤ 50
4x + y ≤ 28
2. Objective function:
z = 10x + 7y
Constrains:
x ≥ 0
t ≥ 0
2x + y ≤ 100
x + y ≤ 75