Um Hello My Question is what is 2/3 x 5

Pls answer ASAP

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?

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10

Can someone answer this question for me