Answer:
m = 4 or m = -8
Step-by-step explanation:
length between 2 points = √(difference of x)² + (difference of y)²
AB² = (m - (-2))² + (5 - 3)² = (m + 2)² + 4 = m² + 4m +8
AC² = ((-1) - (-2))² + (0 - 3)² = 10
AB² = 4AC²
m² + 4m +8 = 40
m² + 4m - 32 = 0
(m - 4) (m + 8) = 0
m = 4 or m = -8
