To isolate \( x \) in the equation, let's go through the given steps and calculations step-by-step.
Starting with your original equation:
\[ 10 + 10x = 30 + 5x \]
To keep \( x \) terms on the left side, subtract \( 5x \) from both sides:
\[ 10 + 10x - 5x = 30 \]
This simplifies to:
\[ 10 + 5x = 30 \]
Next, subtract 10 from both sides:
\[ 5x = 30 - 10 \]
This simplifies to:
\[ 5x = 20 \]
Now, to solve for \( x \), divide both sides by 5:
\[ x = \frac{20}{5} \]
This gives:
\[ x = 4 \]
So, the final value for \( x \) is:
\[ \boxed{4} \]