Xiao Ming's average scores in Chinese and mathematics are 87 points, and his average scores in Chinese, mathematics, and foreign languages are 89 points. How much is his score in foreign languages?
小明语文、数学平均成绩87分，语文、数学、外语平均成绩89分，外语成绩多少分？
<gadget id="calculator">89 * 3</gadget>
<output>267</output>

<gadget id="calculator">87 * 2</gadget>
<output>174</output>

<gadget id="calculator">267 - 174</gadget>
<output>93</output>

<result>93</result>