Multiply $55$ by $ \dfrac{x}{x} $ to get $ \dfrac{ 55x }{ x } $.

Step 1: Write $ 55 $ as a fraction by putting $ \color{red}{1} $ in the denominator.

Step 2: Multiply numerators and denominators.

Step 3: Simplify numerator and denominator.

$$ \begin{aligned} 55 \cdot \frac{x}{x} & \xlongequal{\text{Step 1}} \frac{55}{\color{red}{1}} \cdot \frac{x}{x} \xlongequal{\text{Step 2}} \frac{ 55 \cdot x }{ 1 \cdot x } = \\[1ex] & \xlongequal{\text{Step 3}} \frac{ 55x }{ x } \end{aligned} $$

Add $240$ and $ \dfrac{55x}{x} $ to get $ \dfrac{ \color{purple}{ 295x } }{ x }$.

Step 1: Write $ 240 $ as a fraction by putting $ \color{red}{ 1 } $ in the denominator.

Step 2: To add raitonal expressions, both fractions must have the same denominator.
We can create a common denominator by multiplying the first fraction by $\color{blue}{ x }$.

$$ \begin{aligned} 240+ \frac{55x}{x} & \xlongequal{\text{Step 1}} \frac{240}{\color{red}{1}} + \frac{55x}{x} = \frac{ 240 \cdot \color{blue}{ x }}{ 1 \cdot \color{blue}{ x }} + \frac{ 55x }{ x } = \\[1ex] & \xlongequal{\text{Step 2}} \frac{ \color{purple}{ 240x } }{ x } + \frac{ \color{purple}{ 55x } }{ x }=\frac{ \color{purple}{ 295x } }{ x } \end{aligned} $$