Question

$M$ is the midpoint of the straight line $PQ$. If $P$ is $(-2,9)$ and $M$ is (4, 3), find the coordinates of $Q.$

• A. $(1,6)$
• B. $(10,-3)$
• C. $(10,6)$
• D. $(8,-3)$

Answer 1

Answer: (B)

$(10,-3)$

Let coordinates of $Q$ be $(x,y)$

and midpoints are given as:
$\dfrac{x+(-2)}{2}=4

\dfrac{y+9}{2}=3$

$x-2=8y+9=6$
$\Rightarrow x=10\Rightarrow y=-3$
$\therefore (10,-3)$ are coordinates of $Q$.