Final answer:
The coordinates of point K are (-5, -7).
Step-by-step explanation:
To find the coordinates of point K, we can use the midpoint formula. The midpoint formula states that the coordinates of the midpoint between two points (x1, y1) and (x2, y2) is given by:
M = ((x1 + x2) / 2, (y1 + y2) / 2)
In this case, the coordinates of the midpoint M are (-1, 1) and the coordinates of point J are (3, 9). Plugging these values into the formula, we get:
K = ((3 + x2) / 2, (9 + y2) / 2)
Since we know that the x-coordinate of the midpoint is -1, we can solve for x2:
(3 + x2) / 2 = -1
3 + x2 = -2
x2 = -2 - 3
x2 = -5
Finally, we can substitute the value of x2 into the equation for the y-coordinate:
(9 + y2) / 2 = 1
9 + y2 = 2
y2 = 2 - 9
y2 = -7
Therefore, the coordinates of point K are (-5, -7).