A parabola with a vertex at (0,0) has a directrix that crosses the negative part of the y-axis. Which could be the equation of the parabola?

x2 = –4y
x2 = 4y
y2 = 4x
y2 = –4

Negative 5 1/12 + negative 4 1/4 + 6 3/4

Jacob signs up to work for 2 1/2 hours at the school carnival. if each work shift is 3/4 hour, how many shifts will jacob work? (i just want to double check : |, for anybody that responds! : )

Can someone me out here and the tell me the greatest common factor