To solve the equation \( 3i + 2i - 7 = 18 \), we start by simplifying the left side.
Combine the like terms (the terms with \( i \)):
\[ 3i + 2i = 5i \]
So the equation simplifies to:
\[ 5i - 7 = 18 \]
Next, we'll isolate \( 5i \) by adding 7 to both sides:
\[ 5i = 18 + 7 \]
This simplifies to:
\[ 5i = 25 \]
Now, divide both sides by 5 to solve for \( i \):
\[ i = \frac{25}{5} = 5 \]
Thus, the solution is:
\[ i = 5 \]