F1(0,5√2)
c=5√2
a^2=c^2+b^2=50+b^2
x^2/b^2+y^2/(5)+b^2)=1
x^2/b^2+(3x-2)^2/(50+b^2)=1
(50+10b^2)x^2-12b^2*x-46b^2-b^4=0
x1+x2=12b^2/(50+10b^2)
(x1+x2)/2=1/2
[12b^2/(50+10b^2)]/2=1/2
b^2=25
a^2=50+b^2=75
x^2/25+y^2/75=1