Q. \(\,-1.4x-3.9=-6.4\,\)

We want to solve the equation:

\[
-1.4x – 3.9 = -6.4
\]

Step 1: Add 3.9 to both sides

The term \(-3.9\) is subtracting from \(-1.4x\). To get the \(x\)-term by itself, we add \(3.9\) to both sides.

\[
-1.4x – 3.9 + 3.9 = -6.4 + 3.9
\]

On the left, \(-3.9 + 3.9 = 0\), so they cancel:

\[
-1.4x = -6.4 + 3.9
\]

Compute the right side:

\[
-6.4 + 3.9 = -2.5
\]

So the equation becomes:

\[
-1.4x = -2.5
\]

Step 2: Divide both sides by \(-1.4\)

Now we have \(-1.4x = -2.5\). To isolate \(x\), divide both sides by \(-1.4\).

\[
\frac{-1.4x}{-1.4} = \frac{-2.5}{-1.4}
\]

The \(-1.4\) cancels on the left, leaving just \(x\):

\[
x = \frac{-2.5}{-1.4}
\]

Compute the division:

\[
x = \frac{2.5}{1.4} \;=\; 1.785714\ldots
\]

Final Answer

So, the solution is:

\[
x = 1.785714\ldots
\]

Rounded to two decimal places:

\[
x \approx 1.79
\]