<PRE><B>Question 1184921</B>
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Here first is a formal mathematical solution....&lt;br&gt;
The x coordinate of the midpoint is the average of the x coordinates of the endpoints; the y coordinate of the midpoint is the average of the y coordinates of the endpoints:&lt;br&gt;
The midpoint between A(3,-6) and B(p,q) is M((3+p)/2,((-6+q)/2).&lt;br&gt;
The midpoint is M(1,2). So...&lt;br&gt;
x coordinates:
(3+p)/2=1
3+p=2
p=-1&lt;br&gt;
y coordinates:
(-6+q)/2=2
-6+q=4
q=10&lt;br&gt;
ANSWER: The coordinates of B are (p,q)=(-1,10)&lt;br&gt;
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But you don&#39;t learn much by plugging numbers into formulas; you will understand the problem a lot better if you solve it informally.&lt;br&gt;
Imagine you are walking in a straight line from A(3,-6) towards B, and you are halfway there when you reach (1,2).&lt;br&gt;
At the midpoint (1,2) you have moved -2 units in the x direction -- from 3 to 1.  So to get to the end you need to move another -2 units in the x direction from 1.&lt;br&gt;
1-2=-1; the x coordinate of B is -1.&lt;br&gt;
At the midpoint (1,2) you have moved 8 units in the y direction -- from -6 to 2.  So to get to the end you need to move another 8 units in the y direction from 2.&lt;br&gt;
2+8=10; the y coordinate of B is 10.&lt;br&gt;
ANSWER: B(-1,10)&lt;br&gt;
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