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: 3x^2 +12x -66 =0 giup mik voi

Toán Lớp 9: 3x^2 +12x -66 =0
giup mik voi

Comments ( 2 )

  1. 3x^2+12x-66=0
    ⇔3(x^2+4x-22)=0
    ⇔x^2+4x-22=0
    Δ=b^2-4ac
    ⇔Δ=4^2-(4.1.-22)
    $x_1=\dfrac{-b-\sqrt{Δ}}{2a}=\dfrac{-4-\sqrt{4^2-(4.1.-22)}}{2.1}=-2-\sqrt{26}$
    $x_2=\dfrac{-b+\sqrt{Δ}}{2a}=\dfrac{-4+\sqrt{4^2-(4.1.-22)}}{2.1}=\sqrt{26}-2$
    Vậy S={-2-\sqrt{26};\sqrt{26}-2}

Leave a reply

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

About Ayla