Patrick T. answered 01/23/22
Tutor Specializing in French & Math (up to college Pre-Calculus)
Hello Ronnie,
Let's call M (xM, yM) the midpoint. The midpoint coordinates are given by the equations:
xM = (x1 + x2)/2
yM = (y1 + y2)/2
Let's start with xM. You're given xM = -7 and x1 = -7 so the equation for xM can be written as: -7 = (-7+x2)/2
Multiply both sides of the equation by 2 to get rid of the denominator on the right side and you get:
-14 = -7 + x2
Add 7 on both sides: -7 = x2
Moving on to yM. You're given yM = 4 and y1 = 1 so the equation for yM can be written as: 4 = (1+ y2)/2
Multiply both sides of the equation by 2 to get rid of the denominator on the right side and you get:
8 = 1 + y2
Subtract 1 from both sides: 7 = y2
Let's check by plugging those 2 answers in the midpoint formulas given earlier:
Is -7 = (-7 + -7)/2 true? -7 = -14/2 = -7 TRUE
Is 4 = (1+7)/2 true? 4 = 8/2 = 4 TRUE
So P2 = (-7, 7)