It seems like you have a system of equations here. Let's clear that up and solve it step by step.

The equations can be rewritten as:

1. \( 2.8 - 5 \cdot (x - 10) = -\frac{3}{42} \)
2. \( 8 - 5 \cdot (x - 10) = -\frac{3}{4} \)

**Solve the first equation:**

1. Start with:
\[
2.8 - 5 \cdot (x - 10) = -\frac{3}{42}
\]
Simplifying \(-\frac{3}{42}\) gives:
\[
-\frac{1}{14}
\]

2. The equation becomes:
\[
2.8 - 5(x - 10) = -\frac{1}{14}
\]

3. Subtract \(2.8\) from both sides:
\[
-5(x - 10) = -\frac{1}{14} - 2.8
\]
Converting \(2.8\) to a fraction gives:
\[
2.8 = \frac{28}{10} = \frac{14}{5}
\]
With a common denominator of 70, we can write:
\[
-\frac{1}{14} = -\frac{5}{70}
\]
\[
\frac{14}{5} = \frac{196}{70}
\]
Now substituting gives:
\[
-5(x - 10) = -\frac{5}{70} - \frac{196}{70}
\]
\[
-5(x - 10) = -\frac{201}{70}
\]

4. Divide by -5:
\[
x - 10 = \frac{201}{70 \cdot 5} = \frac{201}{350}
\]
Therefore:
\[
x = 10 + \frac{201}{350} = \frac{3500 + 201}{350} = \frac{3701}{350}
\]

**Solve the second equation:**

1. Start with:
\[
8 - 5(x - 10) = -\frac{3}{4}
\]

2. Subtract \(8\) from both sides:
\[
-5(x - 10) = -\frac{3}{4} - 8
\]
Converting \(8\) to a fraction gives:
\[
8 = \frac{32}{4}
\]
Thus:
\[
-5(x - 10) = -\frac{3}{4} - \frac{32}{4} = -\frac{35}{4}
\]

3. Divide by -5:
\[
x - 10 = \frac{35}{4 \cdot 5} = \frac{35}{20} = \frac{7}{4}
\]
Therefore:
\[
x = 10 + \frac{7}{4} = \frac{40}{4} + \frac{7}{4} = \frac{47}{4}
\]

**Summary of Solutions:**

1. From the first equation, we found \( x = \frac{3701}{350} \) which simplifies very close to \(x = 10.006\).
2. From the second equation, we found \( x = \frac{47}{4} = 11.75\).

Given the two equations result in different values for \(x\), there might be some inconsistency or error in the initial equation you provided. Please feel free to clarify or correct any part of this process for me to assist you further!