Three lines intersect at a common point. In the figure below, m∠1=x°, m∠2=2x°, and m∠3=75°.



Which equations can be used to determine the value of x? Select all that apply.




A:3x°=75°


B:3x°=105°


C:3x°=255°


D:3x°+75°=180°


E:x°+2x°+75°=180°


F:x°+2x°+3x°=360