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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 9: $\sqrt{1+\sqrt{3}+1}$`+`$\sqrt{1-\sqrt{3}+1}$

Toán Lớp 9: $\sqrt{1+\sqrt{3}+1}$+$\sqrt{1-\sqrt{3}+1}$

Comments ( 2 )

  1. Giải đáp+Lời giải và giải thích chi tiết:
     Đặt A=sqrt{1+sqrt3+1}+sqrt{1-sqrt3+1}
              =sqrt{2+sqrt3}+sqrt{2-sqrt3}
      =>Asqrt2=sqrt2.(sqrt{2+sqrt3}+sqrt{2-sqrt3})
           Asqrt2=sqrt{4+2sqrt3}+sqrt{4-2sqrt3}
           Asqrt2=sqrt{3+2sqrt3+1}+sqrt{3-2sqrt3+1}
           Asqrt2=sqrt{(sqrt3+1)^2}+sqrt{(sqrt3-1)^2}
           Asqrt2=|sqrt3+1|+|sqrt3-1|
           Asqrt2=sqrt3+1+sqrt3-1
           Asqrt2=2sqrt3
      =>A=(2sqrt3)/sqrt2
             =sqrt6
     Vậy sqrt{1+sqrt3+1}+sqrt{1-sqrt3+1}=sqrt6

  2. #tnvt
    \sqrt{1+\sqrt{3}+1]+\sqrt{1-\sqrt{3}+1}
    =\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}
    =\frac{\sqrt{2}(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}})}{\sqrt{2}}
    =\frac{\sqrt{4+2\sqrt{3}}+\sqrt{4-2\sqrt{3}}}{\sqrt{2}}
    =\frac{\sqrt{(\sqrt{3}+1)^2}+\sqrt{(\sqrt{3}-1)^2}}{\sqrt{2}}
    =\frac{|\sqrt{3}+1|+|\sqrt{3}-1|}{\sqrt{2}}
    =\frac{\sqrt{3}+1+\sqrt{3}-1}{\sqrt{2}}
    =\frac{2\sqrt{3}}{\sqrt{2}}
    =\sqrt{6}

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222-9+11+12:2*14+14 = ? ( )