Find the midpoint (6,-7) and (4,1)

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.

Xy x xy if a and b are positive integers such that a*b=9 and b*a=72 what is the value of a/b

Astudent showed the steps below while solving the inequality |x-4|< 1 by graphing.