Supplementary= 180 degrees.
So, they both equal 180 degrees together.
3(x+3)+ 2(3+x)= 180
Distribute.
3x+9+6+2x= 180
Combine like terms.
5x+15= 180
Subtract 15 on both sides.
5x= 165
Divide both sides by 5.
x= 33
Plug in x.
3(33+3)= 108
2(3+33)= 72
m<CDF= 108
m<EDF= 72
I hope this helps!
~kaikers