Two cars drive opposite each other from places A and B. Car A travels 45 kilometers per hour, and car B travels 50 kilometers per hour. Car B starts after 3 hours. After 4 hours, the two cars meet, how far is the distance between the two places?
两辆车从甲乙两地相对开出，甲车每小时行45千米，乙车每小时行50千米，甲车出发3小时后，乙车才出发．4小时后两车相遇，两地相距多远？
<gadget id="calculator">45 * 3</gadget>
<output>135</output>

<gadget id="calculator">45 + 50</gadget>
<output>95</output>

<gadget id="calculator">95 * 4</gadget>
<output>380</output>

<gadget id="calculator">135 + 380</gadget>
<output>515</output>

<result>515</result>