Answer
AB = 10 units
Step-by-step explanation
The distance between two points with the coordinates (x₁, y₁) and (x₂, y₂) is given as
d = √[(x₂ - x₁)² + (y₂ - y₁)²]
For this question,
(x₁, y₁) and (x₂, y₂) are A (-1, 1) and B (-9, 7)
x₁ = -1
y₁ = 1
x₂ = -9
y₂ = 7
d = √[(x₂ - x₁)² + (y₂ - y₁)²]
d = √[(-9 - (-1))² + (7 - 1)²]
d = √[(-9 + 1)² + (6)²]
d = √[(-8)² + (6)²]
d = √[(64 + 36]
d = √(100)
d = 10 units
Hope this Helps!!!