The variables a, b, and c represent polynomials where a = x + 1, b = x2 + 2x − 1, and c = 2x. what is ab + c in simplest form? x3 + 3x − 1 x3 + 4x − 1 x3 + 3x2 + 3x − 1 x3 + 2x2 − x + 1

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.