Cars A and B start from two places at the same time, drive opposite each other, and meet each other after 7 hours. Car A is 20 kilometers slower than car B per hour, and the speed ratio of the two cars is 7:9. Find the distance between the two places?
甲乙两车从两地同时出发，相对而行，7小时候相遇．甲车每小时比乙车慢20千米，两车的速度比为7：9．求两地的距离？
<gadget id="calculator">9 - 7</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">7 * 10</gadget>
<output>70</output>

<gadget id="calculator">9 * 10</gadget>
<output>90</output>

<gadget id="calculator">70 + 90</gadget>
<output>160</output>

<gadget id="calculator">160 * 7</gadget>
<output>1_120</output>

<result>1_120</result>