Let's begin by identifying key information given to us:
New size: Height = 18 in, Width = ?
Old size: Height = 2 in, Width = 1 in
We will get the width of the new photo by following the explanation below:
![\begin{gathered} 18\colon2=x\colon1 \\ \Rightarrow(18)/(2)=(x)/(1) \\ \text{Cross multiply, we have:} \\ 2\cdot x=18\cdot1\Rightarrow2x=18 \\ 2x=18 \\ \text{Divide both sides by ''2'', we have:} \\ x=(18)/(2)=9 \\ \therefore x=9in \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/u7ptta2ktafqglu5ghav42vf8rgbq7oz7n.png)
Therefore, the width of the enlarged photo is 9 inches