The teacher will be very surprised to see your correct solution 😉
2 2 110 + y - 20*x + 2*x + 16*y = 0
2*x^2 - 20*x + y^2 + 16*y + 110 = 0
2 2
\tilde x \tilde y
---------- + --------- = 1
2 2
// ___\\ / 1\
||\/ 2 || \2 /
||-----||
|\ 2 /|
|-------|
\ 1/2 / (5, -8)
|a11 a12|
I2 = | |
|a12 a22| |a11 a13| |a22 a23|
K2 = | | + | |
|a13 a33| |a23 a33| |2 0|
I2 = | |
|0 1| | 2 -10| |1 8 |
K2 = | | + | |
|-10 110| |8 110| 2 2
\tilde x \tilde y
---------- + --------- = 1
2 2
// ___\\ / 1\
||\/ 2 || \2 /
||-----||
|\ 2 /|
|-------|
\ 1/2 /