To transform the equation \(-10x + 13 + 12x = 5x - 8\) into the form \(x = a\), we need to simplify and combine like terms properly.
Let's analyze the provided options:
Option A: Subtract \(10x\) from both sides of the equation and then simplify.
This would give us:
\(-10x + 12x + 13 = 5x - 10x - 8\)
\(2x + 13 = -5x - 8\), which can complicate the process.
Option B: Combine like terms \(10x\) and \(12x\) to get \(22x\), and then subtract \(22x\) from both sides of the equation.
This step is incorrect since there is no \(10x\) on the left side of the equation.
Option C: Add \(5x\) to both sides of the equation and then simplify.
This would give us:
\(-10x + 12x + 5x + 13 = -8\)
Which simplifies incorrectly since it would not lead directly to a solvable form.
Option D: Subtract \(13\) from both sides of the equation and then simplify.
This would give:
\(-10x + 12x = 5x - 8 - 13\)
or
\(2x = 5x - 21\). This might lead to simplifying further, but not directly toward \(x = a\).
Option E: Add \(8\) to both sides of the equation and then simplify.
This gives us:
\(-10x + 13 + 12x + 8 = 5x\)
or
\(2x + 21 = 5x\).
So among all these options, none seem to directly lead toward the simplest \(x = a\) format with one clear solution.
However, let’s start by simplifying our original equation step-by-step to determine which transformations yield the one solution:
The initial equation is:
\(-10x + 12x + 13 = 5x - 8\)
Combining \( -10x\) and \(12x\), we have:
\(2x + 13 = 5x - 8\).
Subtract \(5x\) from both sides:
\(2x - 5x + 13 = -8\)
which simplifies to:
\(-3x + 13 = -8\)
Then, subtract \(13\) from both sides:
\(-3x = -8 - 13\)
\(-3x = -21\)
Finally, divide both sides by \(-3\):
\(x = 7\).
This verifies that combining like terms was indeed essential and understood clearly.
Given that closer analysis reveals every path leads to the same, as none of the given are strictly leading to the end transformation straight as \(x = a\), I still suggest:
Ultimately, unless additional steps becoming precise as required do line up from it, Option A would have yielded progress towards arriving at one solution accurately but would lead more intricate results than needed. Thus, starting from there allows a clearer progression.
In essence—no singularly clear option suffices as always valid but consider Boxed selections as more pruning methods.