Two cargo ships are carrying coal. The first cargo ship weighs 1.7 x 104 tons. The second cargo ship weighs 2.4 x 105 tons. How much do both cargo ships weigh? A 7.0 x 102 tons B 4.01 x 108 tons C 2.57 x 105 tons D 4.1x109 tons

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.