Răspunsuri

2014-08-05T12:51:43+03:00
|-2x +1|=7  =>

=>  -2x+1=7   ∧   -2x+1= -7
       -2x = 6            -2x = -8
          x= -3∉N           x=4 ∈ N   =>S(x)={4}
2014-08-05T12:52:49+03:00
-2x+1=7
-2x=7-1
-2x=6
x=6/-2
x=3