task/29845667 Сократить дробь
1) (y+3)/(2y+2)-(y+1)/(2y-2)+3/(y²-1) =(y+3)/2(y+1)-(y+1)/2(y -1) +3/(y² -1) =
[ (y -1)(y+3) - (y+1)²+6] /2(y²-1) =2/2(y²-1) = 1/(y² -1 ) .
2) (2b²-b) /(b³+1) - (b-1)/(b²-b +1) =(2b²-b- (b-1)(b+1) ) / (b+1)(b² -b +1) = (b² -b +1) / (b+1)(b² -b +1) = 1 / (b +1) .