Номер 1 и 2, умоляю!!!
1) (2 -n)(2+n)/4n(2 -n) =(2 +n)/4n 2) 6/x(x+3) -2/x =(6 -2(x+3)) /x(x+3) =(6 -2x -6) /x(x+3) =(-2x)/x(x+3) =(-x)/(x+3) 3) 5b/(a² -ab) *(a² -b²)/10b² =5b(a-b)(a+b) /a(a-b)10b² =(a+b) /2ab