You want to do some sightseeing from the sky, so you want to rent a helicopter. One service charges $100 plus $80 per hour. Another service

charges $250 plus $70 per hour. At what number of hours will the cost to

fly in the helicopter be the same? *

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.