What is 1/5 times 7 pls help

Aprojectile is thrown upward so that its distance above the ground after t seconds is given by the function h(t) = -16t2 + 704t. after how many seconds does the projectile take to reach its maximum height?

W-16=-12 solve each one step equation plz

Lana's family entered a 5-kilometer race lana's average step length is about 0.5 meter how many steps will she need to take the finish