You can use SAS, or Side Angle Side. Because BC equals EC and AC equals DC, you can get two sides. Also, angle BCA and DCE have the same angle measurement, so you can conclude, using SAS, that BA equals to ED. Also, you can also prove that these two triangles are congruent and that all of the angles are the same as well because all of the side lengths are equal.
1/4(q-12) + 1/3(q+9), Then you must use the distributive property to get 1/q-3+1/3q+3. Then you simplify by combining like terms to get, 7/12q. You do not have any constants because they cross each other out.
