If BC bisects BED, this means that BED is split into two equal parts and that CED = BEC. We can see that AD forms a straight line, which means BED and AEB must be supplementary, ow have a sum of 180 degrees. Since CED has the same angle measure as BEC, this means that BED can be found by multiplying as shown:
![BED = 2(CED) --> 2(4x + 1) --> BED = 8x + 2](https://img.qammunity.org/2019/formulas/mathematics/high-school/zmuuy0neitn8zfkndzebih8apdy5wdqk2n.png)
Now find the value of x:
![11x - 12 + 8x + 2 = 180](https://img.qammunity.org/2019/formulas/mathematics/high-school/5k03t2a138vzay0yky2hov4ecwz9j9di1a.png)
Combine like terms:
![11x + 8x - 12 + 2 = 180](https://img.qammunity.org/2019/formulas/mathematics/high-school/b4jzc3p8pah0gfwvtmyabxnhnt15xyze7n.png)
-->
![19x - 10 = 180](https://img.qammunity.org/2019/formulas/mathematics/high-school/ej4mof9jz5dtgwqvi562a4bmkq5n6m5q83.png)
--->
![19x - 10 + 10 = 180 + 10 --> 19x = 190](https://img.qammunity.org/2019/formulas/mathematics/high-school/3p7r13bizhr42ryyd0jv90d4z42wtzxwxt.png)
Isolate x -->
![(19x)/(19) = (190)/(19)](https://img.qammunity.org/2019/formulas/mathematics/high-school/7zicp1wmusah6ewgrnik0r5qlg9nrdbpth.png)
x = 10
Plug in the value of x:
![AEB + BEC = ?](https://img.qammunity.org/2019/formulas/mathematics/high-school/wy5o9c6kcv63qw611hqtrv0rpo6w1nykdo.png)
-->
![11(10) - 12 + 4(10) + 1AEC](https://img.qammunity.org/2019/formulas/mathematics/high-school/52qpkche8lw0xcj24tmowktjnvv9k9qf78.png)
--->
![110 - 12 + 40 + 1 = AEC](https://img.qammunity.org/2019/formulas/mathematics/high-school/pjf998rmll0slh8u2auwjh3ptgj8r79s1o.png)
---->
![98 + 41 = AEC](https://img.qammunity.org/2019/formulas/mathematics/high-school/jng1hvyc99l6siznv38bgsuqo4z63v5r89.png)
So AEC is 139 degrees.