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

Toán Lớp 9: $\sqrt{6+\sqrt{5}}`-`$\sqrt{29-12\sqrt{5}}$ Câu cuối cùng, RG nha mn

Toán Lớp 9: $\sqrt{6+\sqrt{5}}-$\sqrt{29-12\sqrt{5}}$
Câu cuối cùng, RG nha mn

Comments ( 2 )

  1. Sửa đề ở phần bình luận.
    \sqrt{6+2\sqrt{5}}-\sqrt{29-12\sqrt{5}}
    =\sqrt{5+2.\sqrt{5}.1+1}-\sqrt{20-2.2\sqrt{5}.3+9}
    =\sqrt{(\sqrt{5}+1)^2}-\sqrt{(\sqrt{20}-3)^2}
    =|\sqrt{5}+1|-|\sqrt{20}-3|
    =\sqrt{5}+1-\sqrt{20}+3
    =\sqrt{5}+1-2\sqrt{5}+3
    =4-\sqrt{5}
     

  2. #tnvt
    \sqrt{6+2\sqrt{5}}-\sqrt{29-12\sqrt{5}}(đề đã sửa phần bình luận)
    =\sqrt{5+2\sqrt{5}.1+1}-\sqrt{20-2.2\sqrt{5}.3+9}
    =\sqrt{(\sqrt{5}+1)^2}-\sqrt{(2\sqrt{5}-3)^2}
    =|\sqrt{5}+1|-|2\sqrt{5}-3|
    =\sqrt{5}+1-2\sqrt{5}+3
    =4-\sqrt{5}
     

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