70°
Answer:
160°
Step-by-step explanation:
[tex](3x - 5) \degree + (4x + 10) \degree = 180 \degree \\ (straight \: line \: \angle s) \\ (7x + 5) \degree = 180 \degree \\7x + 5 = 180 \\ 7x = 180 - 5 \\ 7x = 175 \\ x = \frac{175}{7} \\ \huge \orange{ \boxed{x = 25}} \\ \\ m\angle BEC = (3x - 5) \degree \\ m\angle BEC = (3 \times 25 - 5) \degree \\ m\angle BEC = (75 - 5) \degree \\ \huge \red{ \boxed{m\angle BEC = 70 \degree}} \\ \\ by \: remote \: interior \: angle \: theorem : \\ m\angle ABE = m\angle BEC + m\angle BCE \\ m\angle ABE = 70 \degree + 90 \degree \\ \huge \purple{ \boxed{m\angle ABE = 160 \degree }}[/tex]