3040.sagews

var("x y")

(x, y)

q=100

a = implicit_plot(-2*x+3==y, (x,-10,10), (y,-20,20), color="red")

b = implicit_plot(3*x^2+y^2==q, (x, -10,10), (y, -20,20), color="blue")

show(a+b)

c1 = implicit_plot(5*x^2+6*x*y+2*y^2 ==q, (x, -30,30), (y, -30,30), color="green")

c2 = implicit_plot(3*x^2+4*x*y+y^2 ==q, (x, -30,30), (y, -30,30), color="yellow")

show(c1+c2)