Kis equal to l m is equal to n as the angles are marked, what's x and y

X - y + x + y = 180
2x = 180
  x = 90
2x - 2y = x + y
  x = 3y
  y = x/3
  y = 90/3
  y = 30

x - y = 90 - 30 = 60
x + y = 90 + 30 = 120
2x - 2y = 180 - 60 = 120

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!