Question 166195
the form of the equation with foci in the (0,plus or minus c) where c is the foci.

is {{{(x^2/b^2)+(y^2/a^2)=1}}}

a=10/2=5 and to get b{{{4^2+b^2=5^2}}} where c and b are the legs and a is the hypothenuse..... so b=3

equation {{{(x^2/3^2)+(y^2/5^2)=1}}} or {{{25x^2+9y^2=225}}}