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

Toán Lớp 9: Rút gọn a. $\frac{2\sqrt[]{2}-4 }{4-\sqrt[]{2}}$ b.$\frac{\sqrt[]{15}-2\sqrt[]{3} }{2-\sqrt[]{5}}$-$\frac{\sqrt[]{6}-\sqrt[]{3} }{\sq

Home/ Toán Lớp 9: Rút gọn a. $\frac{2\sqrt[]{2}-4 }{4-\sqrt[]{2}}$ b.$\frac{\sqrt[]{15}-2\sqrt[]{3} }{2-\sqrt[]{5}}$-$\frac{\sqrt[]{6}-\sqrt[]{3} }{\sq

Toán Lớp 9: Rút gọn a. $\frac{2\sqrt[]{2}-4 }{4-\sqrt[]{2}}$ b.$\frac{\sqrt[]{15}-2\sqrt[]{3} }{2-\sqrt[]{5}}$-$\frac{\sqrt[]{6}-\sqrt[]{3} }{\sq

Tháng Tám 30, 2022 Toán học 2 Comments 0 views

Toán Lớp 9: Rút gọn
a. $\frac{2\sqrt[]{2}-4 }{4-\sqrt[]{2}}$
b.$\frac{\sqrt[]{15}-2\sqrt[]{3} }{2-\sqrt[]{5}}$-$\frac{\sqrt[]{6}-\sqrt[]{3} }{\sqrt[]{2}}$

Comments ( 2 )

  1. ankim
    ankim
    30 Tháng Tám, 2022 at 5:11 sáng
    Reply
    Giải đáp+Lời giải và giải thích chi tiết:
    a) \frac{2\sqrt{2} – 4}{4 – \sqrt{2}}
    = \frac{2\sqrt{2}(1 – \sqrt{2})}{\sqrt{2}(2\sqrt{2} – 1)}
    = \frac{2\sqrt{2}(1 – \sqrt{2})}{\sqrt{2}(\sqrt{2} – 1)(2 + \sqrt{2} + 1)}
    = \frac{-2}{3 + \sqrt{2}}
    = \frac{2(3 – \sqrt{2})}{7}
    = \frac{6 – 2\sqrt{2}}{7}
    b) \frac{\sqrt{15} – 2\sqrt{3}}{2 – \sqrt{5}} – \frac{\sqrt{6} – \sqrt{3}}{\sqrt{2}}
    = \frac{\sqrt{3}(\sqrt{5} – 2)}{2 – \sqrt{5}} – \frac{\sqrt{12} – \sqrt{6}}{2}
    = – \sqrt{3} – \frac{\sqrt{12} – \sqrt{6}}{2}
    = \frac{-2\sqrt{3} – 2\sqrt{3} + \sqrt{6}}{2}
    = \frac{\sqrt{6} – 4\sqrt{3}}{2}

  2. hongocha12
    hongocha12
    30 Tháng Tám, 2022 at 5:11 sáng
    Reply
    #tnvt
    a)\frac{2\sqrt{2}-4}{4-\sqrt{2}}
    =\frac{(2\sqrt{2}-4)(4+\sqrt{2})}{16-2}
    =\frac{8\sqrt{2}+4-16-4\sqrt{2}}{14}
    =\frac{4\sqrt{2}-12}{14}
    =\frac{2\sqrt{2}-6}{7}
    b)\frac{\sqrt{15}-2\sqrt{3}}{2-\sqrt{5}}-\frac{\sqrt{6}-\sqrt{3}}{\sqrt{2}}
    =\frac{\sqrt{3}(\sqrt{5}-2)}{2-\sqrt{5}}-\frac{\sqrt{2}(\sqrt{6}-\sqrt{3})}{2}
    =-\sqrt{3}-\frac{\sqrt{12}-\sqrt{6}}{2}
    =\frac{-\sqrt{6}-2\sqrt{3}+\sqrt{6}}{2}
    =\frac{-2\sqrt{3}}{2}
    =-\sqrt{3}

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

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