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 10: Vecto a ( -6 ; 1) b ( 2;5) c. ( 7;3) Tìm m sao cho vecto c= mA +mB

Toán Lớp 10: Vecto a ( -6 ; 1) b ( 2;5) c. ( 7;3) Tìm m sao cho vecto c= mA +mB

Comments ( 1 )

  1. Tìm m sao cho \vec{c}=m\vec{a}+m\vec{b}  (1)
    Thay \vec{a}=(-6;1),\vec{b}=(2;5),\vec{c}=(7;3) vào (1) ta có:
    (7;3)=m(-6;1)+m(2;5)
    <=>(7;3)=(-6m;m)+(2m;5m)
    <=>(7;3)=(-6m+2m;m+5m)
    <=>(7;3)=(-4m;6m)
    <=>$\begin{cases}-4m=7\\6m=3 \end{cases}$<=>$\begin{cases}m=-\dfrac{7}{4}\\m=\dfrac{1}{2}\end{cases}$
    Vậy m=-7/3;m=1/2 là giá trị cần tìm.

Leave a reply

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

About Lan Lan