Show that the line `x^(2)-4xy+y^(2)=0` and `x+y=3` from an equilateral triangle.

Show that the straight line x^2-4xy+y^2=0 and x + y = 3 form an equilateral triangle.

Show that the common tangents to the parabola y^2=4x and the circle x^2+y^2+2x=0 form an equilateral triangle.

Show that the lines are 3x+2y+9=0 and 12x+8y-15=0 are parallel lines.

Show that the lines are 3x+2y+9=0 and 12x+8y-15=0 are parallel lines.

Show that the lines are 3x+2y+9=0 and 12x+8y-15=0 are parallel lines.

Show that the straight line x-2y+3=0 and 6x+3y+8=0 are perpendicular .

Show that the equation 4x^(2)+4xy+y^(2)-6x-3y-4=0 represents a pair of parallel lines. Find the distance between them.