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

Toán Lớp 9: Bài 1:Tính a,√8 – √72 + √98 b,2 √27 + √(1- √3) ² -7 √3

Toán Lớp 9: Bài 1:Tính
a,√8 – √72 + √98
b,2 √27 + √(1- √3) ² -7 √3

Comments ( 2 )

  1. a)\sqrt{8}-\sqrt{72}+\sqrt{98}
    =2\sqrt{2}-6\sqrt{2}+7\sqrt{2}
    =3\sqrt{2}
    b)2\sqrt{27}+\sqrt{(1-\sqrt{3})^2}-7\sqrt{3}
    =2.3\sqrt{3}+|1-\sqrt{3}|-7\sqrt{3}
    =6\sqrt{3}+\sqrt{3}-1-7\sqrt{3}
    =-1

  2. Giải đáp:
    a)\sqrt{8}-\sqrt{72}+\sqrt{98}=3\sqrt{2}
    b)2\sqrt{27}+\sqrt{(1-\sqrt{3})^2}-7\sqrt{3}=-1
    Lời giải và giải thích chi tiết:
    a) \sqrt{8}-\sqrt{72}+\sqrt{98}
    =\sqrt{2^2 .2}-\sqrt{6^2 .2}+\sqrt{7^2 .2}
    =2\sqrt{2}-6\sqrt{2}+7\sqrt{2}
    =3\sqrt{2}
    Vậy  \sqrt{8}-\sqrt{72}+\sqrt{98}=3\sqrt{2}
    b)2\sqrt{27}+\sqrt{(1-\sqrt{3})^2}-7\sqrt{3}
    =2\sqrt{3^2 . 3}+|1-\sqrt{3}|-7\sqrt{3}
    =2.3\sqrt{3}+\sqrt{3}-1-7\sqrt{3}
    =6\sqrt{3}+\sqrt{3}-7\sqrt{3}-1
    =-1
    Vậy 2\sqrt{27}+\sqrt{(1-\sqrt{3})^2}-7\sqrt{3}=-1

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