## Elementary Geometry for College Students (5th Edition)

$x =$24 $y=$-8
$A\parallel$B 2X-Y = 3X +2Y (Vertically opposite angles are equal) X+3Y=0 ...(1) Also X +100 + (2X-Y) = 180 (Sum of angles of a triangle) 3X - Y =80...(2) Using (1) AND (2) and subtracting after multiplying $(1) \times$3 3X +9 Y = 0 3X -Y =80 - + - 10 Y = -80 Y = -8 Putting values in above X+ 3Y =0 X= -3 (-8) X= 24