1) 5√3=8,66...
8<5√3
8 este cel mai mare nr.natural mai mic decat radicalul respectiv
2)24=2³·3
40=2³·5
[24,40]=2³·3·5=120
3) -3-x=4
-x=4+3
-x=7 inmultim cu -1
x=-7
4) {a,b} ip{5,3}
5a=3b=k
5a=k⇒ a=k/5
3b=k⇒ b=k/3
inlocuim in relatia (3a+b)/2b-a
(3k/5+k/3)/(2k/3-k/5)=
(9k/15+5k/15)/(10k/15-3k/15)=
(14k/15)/(7k/15)=
14k/7k=2
deci (3a+b)/(2b-a)=2