Răspuns:
Explicație pas cu pas:
1. 28= 4 x 7 atunci [tex]\sqrt{28} =2\sqrt{7}[/tex]
99=9 x 11 atunci [tex]\sqrt{99} =3\sqrt{11}[/tex]
2400= 4 x 100 x 6 atunci [tex]\sqrt{2400} =20\sqrt{6}[/tex]
2 7= [tex]\sqrt{49} \leq \sqrt{50} =5\sqrt{2}[/tex]
[tex]\sqrt{27} \leq \sqrt{28}[/tex]
3 l [tex]4\sqrt{2} -6[/tex] l = 6-[tex]4\sqrt{2}[/tex] si [tex]\sqrt{32} = 4\sqrt{2}[/tex]
atunci 6-4[tex]\sqrt{2}[/tex] -[tex]4\sqrt{2}[/tex]= 6-8[tex]\sqrt{2}[/tex]
3b 1+3+5+..+99= 1+2+3+...+99-2-4-...-98=(99 x 100)/2 -2(1+2+..+50)=
4950- 2(50x51)/2= 4950-2x 1275=4950- 2550= 2400(continui si tu)
3c. (6-9)^2014= (-3)^2014= 3^2014
