Let X be the charge for an oil change, and let the tax on X be 7% so that the actual charge is 1.07X. Let Y be the number of containers of oil that are needed, and $2 the price per container. Then 2Y is the price of the oil itself. The Cov(X, Y) is 5.6. What is the Cov(1.07X, 2Y)

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.