Let's solve each equation step-by-step.

### Equation t) \( x - (7x + 3) + 4x = 53 \)

1. Distribute the negative sign inside the parentheses:
\[
x - 7x - 3 + 4x = 53
\]

2. Combine like terms:
\[
(x - 7x + 4x) - 3 = 53
\]
\[
(-2x) - 3 = 53
\]

3. Add 3 to both sides to isolate the term with \( x \):
\[
-2x = 53 + 3
\]
\[
-2x = 56
\]

4. Divide both sides by -2 to solve for \( x \):
\[
x = \frac{56}{-2}
\]
\[
x = -28
\]

So, the solution to equation t) is \( x = -28 \).

### Equation u) \( 9(1 - x) - 7(2x - 1) = 211 - (211 + 30) \)

1. Simplify the right-hand side:
\[
211 - (211 + 30) = 211 - 211 - 30 = -30
\]
So the equation becomes:
\[
9(1 - x) - 7(2x - 1) = -30
\]

2. Distribute the constants inside the parentheses:
\[
9 \cdot 1 - 9 \cdot x - 7 \cdot 2x + 7 \cdot 1 = -30
\]
\[
9 - 9x - 14x + 7 = -30
\]

3. Combine like terms:
\[
9 + 7 - 9x - 14x = -30
\]
\[
16 - 23x = -30
\]

4. Subtract 16 from both sides to isolate the term with \( x \):
\[
-23x = -30 - 16
\]
\[
-23x = -46
\]

5. Divide both sides by -23 to solve for \( x \):
\[
x = \frac{-46}{-23}
\]
\[
x = 2
\]

So, the solution to equation u) is \( x = 2 \).

### Summary
- The solution to equation t) is \( x = -28 \).
- The solution to equation u) is \( x = 2 \).