How can you describe three points so that they determine a plane

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

The chs baseball team was on the field and the batter popped the ball up. the equation b(t)=80t-16•16+3.5 represents the height of the ball above the ground in feet as a function of time in seconds. how long will the catcher have to get in position to catch the ball before it hits the ground? round to the nearest second

How can constraints be used to model a real-world situation?