Let p: The day is Tuesday. Let q: The day is Thursday.
Let r: She comes to work.

Which represents the statement "The day is Tuesday or Thursday if and only if she comes to work”?

p ↔ (q ∧ r)
p ↔ (q ∨ r)
(p ∧ q) ↔ r
(p ∨ q) ↔ r

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.

Are the corresponding angles congruent? explain why or why not.

George writes the mixed number as sum and uses the distributive property 1/2.-2/5=1/2-2+2/5=1/2