Răspuns:
a) A=50 (irational)
b) u(A)=u(5+[tex]7^{3} [/tex])=8 (irational)
c) A=(1+199)*100/2=200*100/2=100*100=> A=100 (rational)
d) A=199+2*199*200/2=199+199*200=199(1+200)=199*201 (irational)
29.
a) a={1,4,7}
b) a={5}
c) ab={00,25,50,75}
d) a={2,7}; b={2,6}
e)
b={0,5}
a={7,9}
