Let's solve the expression step by step:
The expression is:
\[ 18 - 9 \frac{4}{9} + \frac{7}{9} - 8 \]
First, let's convert \( 9 \frac{4}{9} \) into an improper fraction:
\[ 9 \frac{4}{9} = 9 + \frac{4}{9} = \frac{9 \times 9 + 4}{9} = \frac{81 + 4}{9} = \frac{85}{9} \]
Now substituting this into the expression:
\[ 18 - \frac{85}{9} + \frac{7}{9} - 8 \]
Now, let's combine the integer parts (18 and -8):
\[ 18 - 8 = 10 \]
So now we have:
\[ 10 - \frac{85}{9} + \frac{7}{9} \]
Combining the fractions:
\[ -\frac{85}{9} + \frac{7}{9} = -\frac{85 - 7}{9} = -\frac{78}{9} \]
Now, combine it with the integer part:
\[ 10 - \frac{78}{9} \]
To subtract these, we need a common denominator. Convert 10 into a fraction:
\[ 10 = \frac{10 \times 9}{9} = \frac{90}{9} \]
Now the expression is:
\[ \frac{90}{9} - \frac{78}{9} = \frac{90 - 78}{9} = \frac{12}{9} \]
Simplifying \( \frac{12}{9} \):
\[ \frac{12}{9} = \frac{4}{3} \]
So, the final result is:
\[ \frac{4}{3} \text{ or } 1 \frac{1}{3} \]