Let last year product be x boxes.
110% of x means [tex]\displaystyle{ \frac{110}{100}\cdot x [/tex].
Thus, we solve the equation:
[tex]\displaystyle{ \frac{110}{100}\cdot x=715,000[/tex].
Multiplying both sides by [tex]\displaystyle{ \frac{100}{110}[/tex], we have:
[tex]\displaystyle{ x=715,000 \cdot \frac{100}{110}=650,000[/tex].
Answer: Last year's annual production was 650,000 boxes.