M \left(-1,5\right) is the midpoint of AB If A has coordinates \left(4,3\right) Find the x coordinate of B. (Use the variable x in your working out
Let the coordinates of point B be (x, y).
Since M is the midpoint of AB, we can use the midpoint formula to find the coordinates of M:
M = [(x1 + x2)/2, (y1 + y2)/2]
And we know that M = (-1, 5) and A = (4, 3).
Therefore,
(-1, 5) = [(4 + x)/2, (3 + y)/2]
Now we can solve for x:
-1 = (4 + x)/2
Multiply both sides by 2:
-2 = 4 + x
Subtract 4 from both sides:
-6 = x
So the x coordinate of B is -6.