Answer:
42°
Step-by-step explanation:
[tex](7x - 2) \degree = (6x + 18) \degree\\ ..(exterior \: alternate \: \angle s) \\ 7x - 2 = 6x + 18 \\ 7x - 6x = 18 + 2 \\ x = 20 \\ \\ (7x - 2) \degree + \angle \: 1 = 180 \degree \\..(straight \: line \: \angle s) \\ (7 \times 20 - 2) \degree+ \angle \: 1 = 180 \degree \\ 138 \degree+ \angle \: 1 = 180 \degree \\ \angle \: 1 = 180 \degree - 138 \degree \\ \angle \: 1 = 42\degree[/tex]
