
David L. answered 08/20/19
Ph.D. Chemist tutoring math and science
One way of answering this question is to use the standard point/slope equation. If a line passes through a point (x1, y1) and has a slope of m, then the point/slope equation states that the equation of the line is given by (y-y1) = m(x-x1). Since a horizontal line has a slope of zero, m=0. Plugging the information into the point/slope equation gives
(y-(-4)) = 0*(x-(-3)). This simplifies to y+4=0, or the final answer of y= -4.