Answer:
-9x + 4y
Explanation:
Adding expressions:
  Like terms have same variable with same power.Combine like terms.
Here, x and (-10x) are like terms &
 (-2y) and 6y are like terms
x - 2y + (-10x + 6y) = x - 2y - 10x + 6y
 = x - 10x - 2y + 6y
 = -9x + 4y