You can determine midpoint by
x-midpoint = (x₁ + x₂)/2
y-midpoint = (y₁ + y₂)/2
Given from the question
x-midpoint = -6
x₁ = -7
y-midpoint = 5
y₁ = 8
Asked from the question
(x₂, y₂)
Solution
Find x₂, input the value of x₁ and x-midpoint to the formula
(x₁ + x₂)/2 = x-midpoint
(-7 + x₂)/2 = -6
-7 + x₂ = -6 × 2
-7 + x₂ = -12
x₂ = -12 + 7
x₂ = -5
Find y₂, input the value of y₁ and y-midpoint to the formula
(y₁ + y₂)/2 = 5
(8 + y₂)/2 = 5
8 + y₂ = 5 × 2
8 + y₂ = 10
y₂ = 10 - 8
y₂ = 2
Answer
P₂ = (-5,2)