Merge pull request #1754 from maths/KZerva-patch-2

Update 2-6-1-6-Find-eq-of-circles.xml

Author: sangwinc

samplequestions/stacklibrary/HELM/Course_quiz_2_6-the-circle/top/Default-for-2-6/2-6-1-6-Find-eq-of-circles.xml

@@ -22,7 +22,7 @@
     </li>
 
     <li>
-        <p>\( C({@x3@}, {@y4@}), \, R= {@r4@} :\) [[input:ans4]] [[validation:ans4]] [[feedback:prt4]]</p>
+        <p>\( C({@x4@}, {@y4@}), \, R= {@r4@} :\) [[input:ans4]] [[validation:ans4]] [[feedback:prt4]]</p>
     </li>
 
 </ol>]]></text>