Cos theta equals zero,

What is the sum or difference 4x10 – 9x10 (1 point) –5x10 –5x20 –36x10 –36x20 this is the cca test i need all the answers this is the first 2

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.

Factor and solve to find roots x squared -x - 90 =0