pakai cara besok mau dikumpul

1) nilai Y 
23 = 4y - 1
23 = 4 × ... - 1
23 = 4 × 6 - 1
23 = 24 - 1
23 = 23
nilai y = 6

nilai x
9 = 2x + 1
9 = 2 × ... + 1
9 = 2 × 4 + 1
9 = 8 + 1
9 = 9
nilai x = 4

2)  a. ∠ABC = ∠ADC
∠ABC = 100°
∠BCD = 360 - (100 + 100 + 95)
∠BCD = 360 - 295
∠BCD = 65°

b. ∠ADC = ∠ABC 
= 360 - (96 + 44)
= 360 - 140
= 220°

∠ADC = 220 : 2
∠ADC = 110°

∠ABC = 220 : 2
∠ABC = 110°

*kata tebal = jawaban
maaf kalau salah ^^