There 80 visitors in a local restaurant. There are only two menu options today: chicken or fish. If 20% of the visitors ordered chicken, how many visitors ordered fish?

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.

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

How do you determine if an ordered pair is a solution to a given equation?