To solve the expression \(18 - 9 \frac{4}{9} + \frac{7}{9} - 8\), we will break it down step by step.
Step 1: Convert the mixed number to an improper fraction
First, we need to convert \(9 \frac{4}{9}\) into an improper fraction.
\[ 9 \frac{4}{9} = 9 + \frac{4}{9} = \frac{9 \times 9 + 4}{9} = \frac{81 + 4}{9} = \frac{85}{9} \]
So the expression now looks like this:
\[ 18 - \frac{85}{9} + \frac{7}{9} - 8 \]
Step 2: Simplify the expression
Combine the constants \(18\) and \(-8\):
\[ 18 - 8 = 10 \]
Now we can rewrite the expression:
\[ 10 - \frac{85}{9} + \frac{7}{9} \]
Step 3: Combine the fractions
Next, combine the fractions \(-\frac{85}{9}\) and \(\frac{7}{9}\):
\[ -\frac{85}{9} + \frac{7}{9} = \frac{-85 + 7}{9} = \frac{-78}{9} \]
Step 4: Rewrite the expression
Now our expression is:
\[ 10 - \frac{78}{9} \]
Step 5: Convert the whole number to a fraction
To subtract the fraction from the whole number, convert \(10\) into a fraction with the same denominator, which is \(9\):
\[ 10 = \frac{90}{9} \]
Step 6: Perform the subtraction
Now we need to subtract \(\frac{78}{9}\) from \(\frac{90}{9}\):
\[ \frac{90}{9} - \frac{78}{9} = \frac{90 - 78}{9} = \frac{12}{9} \]
Step 7: Simplify the fraction
Now simplify \(\frac{12}{9}\):
\[ \frac{12}{9} = \frac{4}{3} \]
Final Result
So the result of the expression \(18 - 9 \frac{4}{9} + \frac{7}{9} - 8\) is:
\[ \frac{4}{3} \]
Or, if you prefer, \(1 \frac{1}{3}\) as a mixed number.