f(x)=ax+b

g(x)=cx+d

h(x)=f(x)g(x)

a = 1 (slider from -5 to 5, step 0.1)
b = -2 (slider from -5 to 5, step 0.1)
c = 3 (slider from -5 to 5, step 0.1)
d = 4 (slider from -5 to 5, step 0.1)
f(x) = a * x + b
g(x) = c * x + d
h(x) = f(x) * g(x)
e: x = (-(a * d + c * b)) / (2 * a * c)
A = Intersect(h, e)
B = Intersect(f, g)
C, D = Intersect(h, f)
E, F = Intersect(h, g)