4. Keisha is the business owner of her own skin care business which sells various organic skin care products. The profit for her business can be modelled by the equation P(x) = -0.5x2 + 6x - 16, where x is the quantity of products sold in hundreds, and P(x) is the profit in thousands of dollars. How many skin care products does she need to sell for her business to break-even? 3