Answer:
[tex](-1,8)[/tex]
Step-by-step explanation:
1) Completing the question:
Midpoint (1,4) Endpoint (3,0)
2) Since the Midpoint equation is:
[tex]Midpoint=\left ( \frac{x_{1}+x_{2}}{2},\frac{y_{1}+y_{2}}{2} \right )[/tex]
Then let's plug the known values into that formula:
[tex](1,4)=\left ( \frac{3+x_{2}}{2},\frac{0+y_{2}}{2} \right )\\\frac{3+x_{2}}{2}=1 \:\: Cross\:Multiplying\\x_{2}=2-3\\x_{2}=-1\\\frac{0+y_{2}}{2} =4\:\:Cross\:Multiplying\\y_{2}=8\\\left (x_{2} ,y_{2} \right )=\left ( -1,8 \right )[/tex]
3) We can check it by plugging the points into the formula.
[tex](1,4)=\left ( \frac{3-1}{2},\frac{0+8}{2} \right )\Rightarrow (1,4)=(1,4)[/tex]