Testul 1
2.
a=2·(1+2+3+...+20)-20
a=2·210-20
a=400 este patrat perfect =>√a=√400=20
3.
√1024 l 32
9 l 62·2 =>√1024=32
____
124
124
______
===
4.
√(1+9+6)+√(1+2)+3√(16/9)=
√16+√3+3·4/3=
4+√3+4=
8+√3
6.
X<√50
X<√(2·5²)
X<5√2
X∈Z =>X∈{5}
Testul 2
2.
[tex] \frac{ \sqrt{27} }{ \frac{9}{2}* \frac{2}{9} } = \frac{ \sqrt{189+36} }{x} [/tex]
[tex] \frac{3 \sqrt{3} }{1} = \frac{15}{x} =\ \textgreater \ x= \frac{15}{3 \sqrt{3} } = \frac{15 \sqrt{3} }{9} = \frac{5 \sqrt{3} }{3} [/tex]
3.
√2025 l 45
16 l 85·5 =>√2025=45
___
425
425
______
===
4.
√(9+7)-3√(12/9·1/3)+√(1+8+27)+√5²(40-4)=
√16-3√(4/9)+√36+√(25·36)=
4-3·2/3+6+5·6=
4-2+6+30=
38
6.
X<√23
X∈Z =>X∈{4}
