Explanation:
m∠1 + m∠2 = 180°
(4x - 20) + (x - 15) = 180°
4x + x - 20 - 15 = 180°
5x - 35 = 180°
5x = 180° + 35°
5x = 215°
x = 215/5
x = 43°
5.1m questions
6.7m answers