A truck can be rented from Company for 50 dollars a day plus 0.50 per mile. Company B charges 30 dollars a day plus 0.90 per mile to rent the same truck. Find the number of miles in a day at which the rental costs for company A and company B are 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.