Aprojectile is thrown upward so that its distance above the ground after t seconds is given by the function h(t) = -16t2 + 640t. after how many seconds does the projectile take to reach its maximum height? show your work for full credit.

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

Hector and alex traded video games. alex gave hector one fourth of his video games in exchange for 6 video games. then he sold 3 video games and gave 2 video games to his brother. alex ended up with 16 video games. how many video games did alex have when he started?

Explain how you can find the missing fraction in 3 4/5 / (blank) 2 5/7. then find the missing fraction.