Solve it graphically

Let A represents the number of ads to be placed in magazine A

Let B represents the number of Ads in magazine B

Objective function

Maximize E= 1,500,000A + 800,000B

Subject to 7000A+3000B <= 250,000

7000A+3000B >= 100,000

A<= 52

B <= 12

A, B >=0