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

Toán Lớp 9: B1 A=(√√5+3 – √3-√5)² B2 A= 3+2√3/√3 – 1/√3-√2 + 2+√2/√2+1 Giúp mik vs ạ Hứa 5 sao!

Toán Lớp 9: B1 A=(√√5+3 – √3-√5)²
B2 A= 3+2√3/√3 – 1/√3-√2 + 2+√2/√2+1
Giúp mik vs ạ
Hứa 5 sao!

Comments ( 1 )

  1. Giải đáp:
    1) A=2
    2) B= 2
    Lời giải và giải thích chi tiết:
    1) A=(\sqrt{\sqrt{5}+3}-\sqrt{3-\sqrt{5}})^2
    =\sqrt{5}+3-2.\sqrt{(\sqrt{5}+3).(3-\sqrt{5})}+3-\sqrt{5}
    =\sqrt{5}-\sqrt{5}+3+3-2\sqrt{3^2-(\sqrt{5})^2}
    =6-2.\sqrt{4}=6-2.2=2
    Vậy: A=(\sqrt{\sqrt{5}+3}-\sqrt{3-\sqrt{5}})^2=2
    $\\$
    2) B={3+2\sqrt{3}}/\sqrt{3}-1/{\sqrt{3}-\sqrt{2}}+{2+\sqrt{2}}/{\sqrt{2}+1}
    ={\sqrt{3}.(\sqrt{3}+2)}/\sqrt{3}-{\sqrt{3}+\sqrt{2}}/{(\sqrt{3}-\sqrt{2}).(\sqrt{3}+\sqrt{2})}+{\sqrt{2}.(\sqrt{2}+1)}/{\sqrt{2}+1}
    =\sqrt{3}+2-{\sqrt{3}+\sqrt{2}}/{3-2}+\sqrt{2}
    =\sqrt{3}+2-(\sqrt{3}+\sqrt{2})+\sqrt{2}
    =\sqrt{3}-\sqrt{3}+\sqrt{2}-\sqrt{2}+2=2
    Vậy: B={3+2\sqrt{3}}/\sqrt{3}-1/{\sqrt{3}-\sqrt{2}}+{2+\sqrt{2}}/{\sqrt{2}+1}=2

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

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