Use the Exterior Angle theorem to solve for x

The multiplication property of zero states that the product of any number and 0 is 0. what must be true about either a or b to make ab=0

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)