The coordinates of the vertices of quadrilateral HIJK are H (1,4) I (3,2) J (-1,-4) K (-3,-2). If quadrilateral HIJK is rotated 270º about the origin, what are the vertices of the resulting image, quadrilateral H'I'J'K'?

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

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.