Lin and diego are discussing the two expression x2 and 2x.

lin says, " i think the two expressions are equivalent."

diego says, "i think the two expression are only equal for some values of x."

do you agree with either of them? explain or show your reasoning. consider making a table like the one below to start or explain your thinking.

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.