All of my friends like fruit. 9 friends like bananas, 8 friends like oranges, and 7 friends like plums. 5 friends like both bananas and oranges, 3 friends like both bananas and plums, 4 friends like both oranges and plums, and 2 friends like bananas, oranges and plums. How many friends do I have?

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.