Mohon dibantu kak

<ul><li>4a + 6 = 42° &nbsp;(sudut dalam berseberangan)</li></ul><p>&nbsp; &nbsp; &nbsp; 4a = 42 - 6</p><p>&nbsp; &nbsp; &nbsp; 4a = 36</p><p>&nbsp; &nbsp; &nbsp; a = 36 : 4&nbsp;</p><p>&nbsp; &nbsp; &nbsp; a = 9°</p><p>&nbsp;</p><ul><li>6b + 108° = 180° &nbsp;(sudut berpelurus)</li></ul><p>&nbsp; &nbsp; &nbsp; 6b = 180° - 108°</p><p>&nbsp; &nbsp; &nbsp; 6b = 72°</p><p>&nbsp; &nbsp; &nbsp; b = 72° : 6</p><p>&nbsp; &nbsp; &nbsp; b = 12°</p><p>&nbsp;</p><ul><li>42° + 6c = 108° (sudut dalam berseberangan)</li></ul><p>&nbsp; &nbsp; &nbsp; 6c = 108° - 42°</p><p>&nbsp; &nbsp; &nbsp; 6c = 66°</p><p>&nbsp; &nbsp; &nbsp; c = 66° : 6</p><p>&nbsp; &nbsp; &nbsp; c = 11°</p><p>&nbsp;</p><ul><li>Menentukan nilai 2a° + b° - 2c°</li></ul><p>&nbsp; &nbsp; &nbsp; &nbsp;2a° + b° - 2c° = 2(9°) + 12° - 2(11°)</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = 18° + 12° - 22°</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = 30° - 22°</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = 8°</p><p>&nbsp;</p><p>Jawaban : <strong>D</strong></p>