An advertising company charges $40 per half - page advertisement and $75 per full-page advertisement. Michael has a budget of $800 to purchase 13 advertisements. A) Define a variable for each unknown. Write a system of equations to represent the situation. B( How many half-page advertisements does Michael purchase? Show Your Work. C) How many full-page advertisements does Michael purchase? Show your Work. ( Will Mark Brainliest but have to show work) Answer A, B & C. No links or nonsense answers please.​