I need help please help me please! A certain radioactive element decays at a rate of 50% each hour. If the initial amount of the element is 9.5 grams, write an equation that represents the amount of the element after x hours. What is the number of grams of this element at 5 hours?

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

What is the percentile for data value 6 in the following data set? 4 13 8 6 4 4 13 6 4 13 2 13 15 5 9 4 12 8 6 13 40 25 35 62

Which statements are true? check all that apply. the line x = 0 is perpendicular to the line y = –3. all lines that are parallel to the y-axis are vertical lines. all lines that are perpendicular to the x-axis have a slope of 0. the equation of the line parallel to the x-axis that passes through the point (2, –6) is x = 2. the equation of the line perpendicular to the y-axis that passes through the point (–5, 1) is y = 1.