11.
a) [tex]|x| = 5 =\ \textgreater \ x[/tex]∈{-5,5}
b) |x| = -2 NU SE POATE (|x|≥0)
c) [tex]|x| = |-7| =\ \textgreater \ |x| = 7 =\ \textgreater \ x[/tex]∈{-7,7}
d) -|x| = 3 NU SE POATE (|x|≥0, deci -|x|≤0)
e) |x-2| = 3 => x∈{-3+2, 3+2} => x∈{-1, 5}
f) |3-x| = 5 => x∈{-2, -8}
g) |2x-3|-4 = 7 => |2x-3| = 11 => x∈{-4, 7}
h) 2|2x+1| = 8 => |2x+1| = 4 => x∈∅
12.
a) |x-2| = |2x-4| => x = 2
b) |3x-5| = |x-7| x = -1
... (Apasa aici pentru a vedea tot)
