posted by Sam .
The coordinates of the vertices of triangle ABC are A (-5,1), B (-2,3) and C (-4,7). The triangle is reflected over the line x=2. What is the sum of the x-coordinates of points A', B' and C'(the points after the reflection)?
The y values will not change,
the new x value will be 2 + (2-oldx)
eg A(-5,1) will become A'(2+(2+5),1) or A'(9,1)
Find B' and C', then add up the x-coordinates.