Let x the number of brochures and y the number of fliers.
Optimizing function⇒ f(x,y) = 0.1 x + 0.06 y
Constraints:
x ≥ 80
y ≥ 100
3x + 2y ≤ 500
See the attached figure which represents the constraints.
From the attached figure:
The vertices of the feasible region are (80, 100), (80, 130) and (100, 100).
Substitute the points (80, 100), (80, 130) and (100, 100). in the function
f(x,y) = 0.1 x + 0.06 y
If (x,y) = (80, 100) ⇒ f(x,y) = 14
If (x,y) = (80, 130) ⇒ f(x,y) = 15.8
If (x,y) = (100, 100) ⇒ f(x,y) = 16
The minimum value 14 at (80, 100).
To minimize the cost, she would print 80 brochures and 100 fliers.