so first off, we know the hyperbola has a horizontal traverse axis, so that means equation wise, the positive fraction is the one with the "x" variable on it, center is the origin, meaning (h,k) is just (0,0), and we know the value for the distances "a" and "c", let's find "b".
![\textit{hyperbola, horizontal traverse axis } \\\\ \cfrac{(x- h)^2}{ a^2}-\cfrac{(y- k)^2}{ b^2}=1 \qquad \begin{cases} center\ ( h, k)\\ vertices\ ( h\pm a, k)\\ c=\textit{distance from}\\ \qquad \textit{center to foci}\\ \qquad √( a ^2 + b ^2) \end{cases} \\\\[-0.35em] ~\dotfill\\\\ \begin{cases} h=0\\ k=0\\ c=71000\\ a=45000 \end{cases}\implies \cfrac{(x- 0)^2}{ 45000^2}-\cfrac{(y- 0)^2}{ b^2}=1 \\\\[-0.35em] ~\dotfill](https://img.qammunity.org/2024/formulas/mathematics/middle-school/9yk6q6k3wacxkytuby7egaiqi13guk3i7m.png)
![\stackrel{c}{71000}=\sqrt{\underset{ a }{45000^2}+b^2}\implies 71000^2=45000^2+b^2 \\\\\\ 71000^2-45000^2=b^2\implies √(71000^2-45000^2)=b\implies 54918.12\approx b \\\\[-0.35em] ~\dotfill\\\\ \cfrac{(x- 0)^2}{ 45000^2}-\cfrac{(y- 0)^2}{ 54918.12^2}=1\implies {\Large \begin{array}{llll} \cfrac{x^2}{ 45000^2}-\cfrac{y^2}{ 54918.12^2}=1 \end{array}}](https://img.qammunity.org/2024/formulas/mathematics/middle-school/f8u7tout49h3u6qenewcdoss0b84apy6h7.png)