minta bantuannya utk soal no. 12-14

nomor 12, jawabannya B
[tex]3x + 2x - 10 = 180 \\ 5x - 10 = 180 \\ 5x = 190 \\ x = \frac{190}{5} \\ x = 38[/tex]


sudut BDC
[tex]2x - 10 \\ = 2.38 - 10 \\ = 76 - 10 = 66[/tex]