Используем формулы (a+b)^2= a^2+2ab+b^2 И (a-b)^2=a^2-2ab+b^2
(53^2+2*53*47+47^2)/(76^2-2*76*51+51^2)=
(53+47)^2/(76-51)^2=
100^2/25^2=
(100/25)^2=4^2=16
Используем формулы (a+b)^2= a^2+2ab+b^2 И (a-b)^2=a^2-2ab+b^2
(53^2+2*53*47+47^2)/(76^2-2*76*51+51^2)=
(53+47)^2/(76-51)^2=
100^2/25^2=
(100/25)^2=4^2=16