Answer:
b = 6
Step-by-step explanation:
[tex](6b - 7) \degree + 90 \degree + 61 \degree = 180 \degree \\ \\ (6b - 7) \degree + 151 \degree = 180 \degree \\ \\ (6b - 7) \degree = 180 \degree - 151 \degree\\ \\ (6b - 7) \degree = 29 \degree \\ \\ 6b - 7 = 29 \\ \\ 6b = 29 + 7 \\ \\ 6b = 36 \\ \\ b = \frac{36}{6} \\ \\ \huge \purple{ \boxed{ b = 6}}[/tex]
