After an airplane flies from A to B at a speed of 750 kilometers per hour, it immediately turns around in the air and returns to A at a speed of 600 kilometers per hour, taking a total of 6.75 hours. What is the air distance between A and B in kilometers?
一架飞机以每小时750千米的速度从甲地飞往乙地后，立即在空中掉头，以每小时600千米的速度按原路返回甲地，一共用6.75小时．甲、乙两地之间的空中距离是多少千米？
<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">6.75 * (4/9)</gadget>
<output>3</output>

<gadget id="calculator">750 * 3</gadget>
<output>2_250</output>

<result>2_250</result>