Students from Class 51 went rowing. They rented some boats. If there were 8 people in each boat, there would be 1 extra person. If there are 9 people in each boat, there are 5 empty seats on the boat. How many boats are rented in total?
五1班的同学去划船，他们租了一些船，如果每船坐8人则多出1人．如果每船坐9人则船上余5个空位，一共租了多少条船．
<gadget id="calculator">1 + 5</gadget>
<output>6</output>

<gadget id="calculator">9 - 8</gadget>
<output>1</output>

<gadget id="calculator">6 / 1</gadget>
<output>6</output>

<result>6</result>