Simplify the expression x^-4/5 * x^7/8

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?

Xy x xy if a and b are positive integers such that a*b=9 and b*a=72 what is the value of a/b

Find the arc length of the semicircle. 7the grade