soal tes camaba , tolong bantu yaa kk' mastah matematika

[tex]\displaystyle (5+4)(5^2+4^2)(5^4+4^4)=\frac{5^2-4^2}{5-4}\cdot\frac{5^4-4^4}{5^2-4^2}\cdot\frac{5^8-4^8}{5^4-4^4}\\(5+4)(5^2+4^2)(5^4+4^4)=\frac{5^8-4^8}{5-4}\\(5+4)(5^2+4^2)(5^4+4^4)=5^8-4^8\\(5+4)(5^2+4^2)(5^4+4^4)=5^8-2^{16}\\\\x+y=8+16\\\boxed{\boxed{x+y=24}}[/tex]