Question 974269
what is the length of the major axis of an ellipse 
(x-1)^2/25 + (y+7)^2/81 = 1
This is an equation of an ellipse with vertical major axis
Its standard form: {{{(x-h)^2/b^2+(y-k)^2/a^2=1}}}, a>b, (h,k)=coordinates of center
For given ellipse:
a^2=81
a=9
length of the major axis=2a=18