The manager of a retail store has figured that her monthly profit P (in thousands of dollars) is determined by her monthly advertising expense x (in tens of thousands of dollars) according to the formula P = x² - 20x² + 110x for 0 ≤ x ≤7. For what value of x does she get $175,000 in profit? The manager gets $175,000 in profit for x= (Round to two decimal places as needed. Use a comma to separate answers as needed.)