tolong dijawab ya beserta caranya

4x + 2x = 90
6x = 90
x = 90/6
x = 15

Jadi sudut BOC = 2x
2(15) = 30°
Jawabannya C
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2x + 10 + 3x + 20 = 180
5x + 30 = 180
5x = 180 - 30
5x = 150
x = 30

Jadi sudut AOB = 2x + 10
2(30) + 10 = 60 + 10
70° , jawabannya D