Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

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

Toán Lớp 9: 4 CAN BAC 20 – 3CAN BAC 125 +5 CAN BAC 45-15 CAN BAC 1 PHAN 5

Toán Lớp 9: 4 CAN BAC 20 – 3CAN BAC 125 +5 CAN BAC 45-15 CAN BAC 1 PHAN 5

Comments ( 2 )

  1. Hướng dẫn trả lời:
    4sqrt{20} – 3sqrt{125} + 5sqrt{45} – 15sqrt{1/5}
    = 4sqrt{4cdot5} – 3sqrt{25cdot5} + 5sqrt{9cdot5} – 3cdot5sqrt{1/5}
    = 4sqrt{2^2cdot5} – 3sqrt{5^2cdot5} + 5sqrt{3^2cdot5} – 3sqrt{5^2cdot1/5}
    = 4cdot2sqrt{5} – 3cdot5sqrt{5} + 5cdot3sqrt{5} – 3sqrt{5}
    = 8sqrt{5} – 15sqrt{5} + 15sqrt{5} – 3sqrt{5}
    = 5sqrt{5}
    Giải đáp:
    = 5sqrt{5}

  2. $4\sqrt{120}$ – $3\sqrt{125}$ + $5\sqrt{45}$ – $15\sqrt{\dfrac{1}{5}}$
    <-> $8\sqrt{5}$ – $15\sqrt{5}$ + $15\sqrt{5}$ – $3\sqrt{5}$$\leftrightarrow$ $8\sqrt{5}$ – $3\sqrt{5}$$\Leftrightarrow$ $5\sqrt{5}$
    vậy đáp số là
    $5\sqrt{5}$

Leave a reply

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

About Kim Dung