Сократите дробь и найдите ее значение при заданных значениях переменных: 

(5x^2+x-4)/(x^2+x)=5[(x-0.8)(x+1)]/x(x+1)=5(x-0.8)/x=5x-4/x=5-4/x
(t^4-bt^2+16)/(t+2)(t^2-4)=[-bt^2-(t^4-16)]/(t^2-4)(t+2)=
-bt^2/(t+2)(t^2-4)-[(t^2-4)(t^2+4)]/(t^2-4)(t+2)=
-bt^2/(t+2)(t^2-4)-[(t-2)(t+2)(t^2+4)]/(t^2-4)(t+2)=
-bt^2/(t+2)(t^2-4)-(t-2)=
=2-t-bt^2/(t+2)(t^2-4)