rezolvare ex.20
x=2^a
a=-1,0,1
A={2⁻¹; 2°; 2¹}={1/2; 1; 2}
y=3^(b-3)
b=2,3,4
B={3²⁻³; 3³⁻³; 3⁴⁻³}={3⁻¹; 3°; 3¹}={1/3; 1; 3}
deci
A={1/2; 1; 2}
B={1/3; 1; 3}
AUB={1/2; 1/3; 1; 2; 3}
A-B={1/2; 1; 2}
AXB={(1/2,1/3); (1/2,1); (1/2,3); (1,1/3); (1,1); (1,3); (2,1/3); (2,1); (2,3)}
AintersectatB={1}
B-A={1/3; 1; 3}
BXA={(1/3,1/2); (1/3,1); (1/3;2); (1,1/2); (1,1); (1,2); (3,1/2);(3,1); (3,3)}
