The amount Mike gets paid weekly can be represented by the expression 2.50a + 290, where a is the number of cell phone accessories he sells that week. What is the constant term in this expression and what does it represent? 2.50a, the amount he earns when he sells a accessories 2.50a, the amount he is guaranteed to be paid each week 290, the amount he earns when he sells a accessories 290, the amount he is guaranteed to be paid each week