−6(x+7)=−4x−2minus, 6, left parenthesis, x, plus, 7, right parenthesis, equals, minus, 4, x, minus, 2 (Choice A)
A
No solutions

(Choice B)
B
Exactly one solution

(Choice C)
C
Infinitely many solutions

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.