Let's solve each equation step by step:

1) (-17) - x - (-28 + 49) = 7

First, simplify the expression inside the parentheses:

(-17) - x - (-28 + 49) = 7
(-17) - x - (-28 + 49) = 7
(-17) - x - 21 = 7

Next, combine like terms:

(-17) - x - 21 = 7
-17 - x - 21 = 7
-38 - x = 7

Now, isolate the variable:

-38 - x = 7
-38 - x + x = 7 + x
-38 = 7 + x

Finally, solve for x:

-38 - 7 = x
-45 = x

Therefore, x = -45.

2) (-35 - x) - 28 = (-128)

First, simplify the expression inside the parentheses:

(-35 - x) - 28 = (-128)
-35 - x - 28 = -128

Next, combine like terms:

-35 - x - 28 = -128
-63 - x = -128

Now, isolate the variable:

-63 - x = -128
-63 - x + x = -128 + x
-63 = -128 + x

Finally, solve for x:

-63 + 128 = x
65 = x

Therefore, x = 65.

3) 11 - (-27 + x) = (-9)

First, simplify the expression inside the parentheses:

11 - (-27 + x) = (-9)
11 - (-27 + x) = (-9)
11 + 27 - x = -9

Next, combine like terms:

11 + 27 - x = -9
38 - x = -9

Now, isolate the variable:

38 - x = -9
38 - x + x = -9 + x
38 = -9 + x

Finally, solve for x:

38 + 9 = x
47 = x

Therefore, x = 47.