2x-y-z=15 4x+5y+2z=10 -X-4y+3z=-20

1: 4 if the wew 35 surfboards at the beach how many were short boards?

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.

Which statement accurately describes how to perform a 90° clockwise rotation of point a (1,4) around the origin?