Point B is at (3,1).
For which segment is B a midpoint?
O AC with endpoints at A(1,-1) and C(5,3)
O AD with endpoints at A(1,-1) and C(6,4)
O AC with endpoints at A(1,-1) and C(8,6)
AC with endpoints at A(1, -1) and C(7,5)

AC with end points A (1,-1) and C (5,3)

Step-by-step explanation:

mid point is calculated using the equation

so from AC, with end points A (1,-1) and C (5,3). If we substitute the values back into the equation.

When we solve we get the same values for the midpoint

sorry I couldn't get Commas so I used dots

step-by-step explanation:

the answer would be  

a.

3: 1

step-by-step explanation: