7. Which expression is equivalent to the expression (5.5 X 107)(3.2 x 10') 2 X 105 A. 8.8 x 1011
B. 8.8 x 1021
C. 1.74 x 105
D. 1.74 x 1017​

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.