To find the number of hours \( h \) Richard needs to work to reach a total of 30 hours for the week, we can set up the equation as follows:
\[ h + 21 \frac{1}{5} = 30 \]
Now we need to convert \( 21 \frac{1}{5} \) into an improper fraction to make calculations easier.
\[ 21 \frac{1}{5} = 21 + \frac{1}{5} = \frac{21 \times 5}{5} + \frac{1}{5} = \frac{105}{5} + \frac{1}{5} = \frac{106}{5} \]
Now we can rewrite the equation:
\[ h + \frac{106}{5} = 30 \]
To isolate \( h \), we will first convert 30 into a fraction with the same denominator of 5:
\[ 30 = \frac{30 \times 5}{5} = \frac{150}{5} \]
Now substitute this back into the equation:
\[ h + \frac{106}{5} = \frac{150}{5} \]
Next, we subtract \( \frac{106}{5} \) from both sides:
\[ h = \frac{150}{5} - \frac{106}{5} = \frac{150 - 106}{5} = \frac{44}{5} \]
To convert \( \frac{44}{5} \) back into a mixed number:
\[ \frac{44}{5} = 8 \frac{4}{5} \]
Thus, the number of hours \( h \) Richard needs to work is:
\[ h = 8 \frac{4}{5} \text{ hours} \]
So the complete working equation and solution are:
\[ h + 21 \frac{1}{5} = 30 \]
\[ h = 8 \frac{4}{5} \text{ hours} \]