9. A company finds that the number of T-shirts it sells the first month the product is introduced is related to the amount they spend on advertising the product. If they spend $40 thousand on advertising, 10 thousand will be sold. However, spending $60 thousand on advertising leads to 14 thousand sold. A. Develop a linear equation in slope-intercept form that describes the relationship between amount spent on advertising in thousands (x) and how many shirts will sell in thousands (y). B. How much should be spent on advertising if the company's goal is to sell 20 thousand shirts