[tex]a= \frac{224,000,000+232,000,000}{2} =228,000,000
\\e=228,000,000-224,000,000=4,000,000
\\e^2=a^2-b^2
\\b^2=a^2-e^2=228,000,000^2-4,000,000^2=228^2\times10^{12}-4^2\times 10^{12}
\\b^2=(228^2-4^2)\times10^{12}=51,968\times 10^{12}
\\b^2=5.1968\times10^{16}
\\
\\ \frac{x^2}{5.1984\times 10^{16}} + \frac{y^2}{5.1968\times10^{16}} =1[/tex]