Supply

Demand

d = 4 (slider from 1 to 4)
s = 3 (slider from 0 to 3)
s1: (5 + s, 5)
d1: (5 + d, 0)
s0: (0 + s, 2)
f = Segment(s0, s1)
d0: (0 + d, 5)
g = Segment(d0, d1)
E = Intersect(g, f)
h = OrthogonalLine(E, xAxis)
i = OrthogonalLine(E, yAxis)
text1: "P = " + (LaTeX[y(E)]) + " \\
Q = " + (LaTeX[x(E)]) + ""