\(A=\frac{595959}{454545}-\frac{14141414}{15151515}\\ A=\frac{595959:10101}{454545:10101}-\frac{14141414:1010101}{15151515:1010101}\\ A=\frac{59}{45}-\frac{14}{15}=\frac{17}{45}\)

\(B=\frac{65+891+135+909}{731-47+69-253}=\frac{\left(65+135\right)+\left(891+909\right)}{\left(731+69\right)-\left(47-253\right)}=\frac{200+1800}{731+69-47+253}=\frac{200+1800}{500}=\frac{2000}{500}=4\)