What is the vertex of f(x) = x² - 10x? Enter your answer in the boxes. What is the y-intercept of f (x) = x² - 10x? Enter your answer in the box. Does f(x) = x² - 10x open upward or downward? upward ○ downward = Graph f(x) = x² - 10x by first plotting its vertex and then its y-intercept.