1) 4,56(1) =(4561-456)/990 =4105/990 =821/198
2) I 5x+1 I =2 explicitam modulul
I 5x+1 I = 5x+1 daca 5x+1 > sau = 0 , x > sau = -1/5 => xe[-1/5 ,+ infinit)
I 5x+1 I =-5x-1 daca 5x -1 ,0 x<1/5 => xe(- infinit , 1/5),
5x+1=2 => 5x=1 => x=1/5
-5x-1 =2 => 5x=-3 => x=-3/5
3) 15/16 +(-3/8):(-9/4) =15/16 + 3/8x4/9 =15/16 + 1/6 =(15x3+8x1)/48 =
=53/48
4) v48 :v3 +(-5/v5) xv10 -(- v50) =
v48 :v3 =v16 =4
-5/v5 =-5v5/5 =-v5 => -v5 xv10 = -v5 xv5xv2 =-5v2
v50 =5v2
E = 4 -5v2 +5v2= 4