Please help ASAP... I’m in a very important test and don’t know answer... will give free points

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?

What is the measure of ac? 5 units 13 units 26 units 39 units 3x- 2b 6x + 9

Sundar used linear combination to solve the system of equations shown. he did so by multiplying the first equation by 5 and the second equation by another number to eliminate the y-terms. what number did sundar multiply the second equation by? 2x+9y=41 3x+5y=36