Answer:
Angle A=87°
Explanation:
(5x-3)°+(4x+21)°=180°
9x°+18°=180°
9x°+18°-18°=180°-18°
9x°=162°
9x°/9°=162°/9°
x=18°
Angle A=(5x18-3)°
(90-3)°
8.5m questions
11.1m answers