Nomor 17 dan 18 yang betul ya

7x + 5x = 180
12x = 180
x = 15
jadi sudut abd = 7x = 7 x 15 = 105

4a-5 + 2a-7 = 90
6a-12 = 90
6a = 90+12
6a = 102
a = 17
jadi sudut abd = 4a-5 = (4x17)-5 = 63

semoga membantu

17.
7x + 5x = 180
12x = 180
x = 15
Sudut ABD = 7x
= 7(15)
= 105°
Jawaban = b. 105°

18.
(4a - 5)+(2a - 7) = 90
6a - 12 = 90
6a = 90+12
6a = 102
a = 17
SudutABD = 4a - 5
= 4(17) - 5
= 63°
jawaban = a.63