From the equation, we have
[tex] h=-20, k =21 , a^2=20^2, b^2=21^2 [/tex]
To find the vertex and focus, we have to use the following formula
[tex] Vertices =(h, k+-a)
\\
Focii = (h,k+-c) [/tex]
And
[tex] c = \sqrt{a^2 + b^2} = \sqrt{400+441} = 29 [/tex]
So, we have
[tex] Vertices=(-21,20+-20)
\\
Focii=(-21, 20+-29) [/tex]
[tex] Vertices =(-21,0),(-21,40)
\\
focii=(-21,-9),(-21,49) [/tex]
