Petra is paying her ten employees for 40 hours a week 52 weeks each year. In 2007 Petra spent___ on wages for her employees each week. When the minimum wage rose in 2009, Petra had to increase her annual budget for wage from 2008 by___.

To calculate Petra's weekly wage expenditure in 2007, we can use the formula:

\[ \text{Weekly wage expenditure} = \text{Number of employees} \times \text{Hours per week} \times \text{Weeks per year} \times \text{Wage per hour} \]

Let's assume a hypothetical wage for each employee. If, for example, Petra pays $10 per hour:

\[ \text{Weekly wage expenditure in 2007} = 10 \, \text{employees} \times 40 \, \text{hours/week} \times 52 \, \text{weeks/year} \times \$10/\text{hour} \]

\[ \text{Weekly wage expenditure in 2007} = \$208,000 \]

Now, for the increase in Petra's annual budget in 2009, we need to know the percentage increase in the minimum wage. Let's assume it's a 10% increase. You can adjust this based on the actual increase.

\[ \text{Increase in annual budget} = 0.10 \times \text{Annual budget for wages in 2008} \]

\[ \text{Increase in annual budget} = 0.10 \times \$208,000 \]

\[ \text{Increase in annual budget} = \$20,800 \]

So, Petra spent \$208,000 on wages each week in 2007, and she had to increase her annual budget for wages by \$20,800 in 2009 due to the minimum wage increase. Keep in mind that these calculations are based on assumptions, and actual figures may vary.