Cho $\overrightarrow {u\,}  = \left( {{m^2} + m - 2\,\,;\,4} \right)$ và $\overrightarrow {\,v}  = (m;2)$. Tìm $m$ để hai vecto \(\overrightarrow u ,\,\,\overrightarrow v \) cùng phương

\(E\left( { - \dfrac{1}{3};\dfrac{1}{3}} \right)\)

\(E\left( { - \dfrac{1}{3};\dfrac{2}{3}} \right)\)

\(E\left( { - \dfrac{1}{3}; - \dfrac{2}{3}} \right)\)  

\(E\left( {\dfrac{1}{3};\dfrac{2}{3}} \right)\)

\(B\left( {5; - 3} \right)\)

\(C\left( { - 3; - 1} \right)\)

\(A\left( {1; - 5} \right)\)

Cả A, B, C đều đúng

\(\overrightarrow c  =  - \dfrac{2}{3}\overrightarrow a  + \dfrac{5}{9}\overrightarrow b \)

\(\overrightarrow c  = \dfrac{1}{3}\overrightarrow a  + \dfrac{4}{9}\overrightarrow b \)

\(\overrightarrow c  = \dfrac{4}{3}\overrightarrow a  + \dfrac{7}{9}\overrightarrow b \) 

\(\overrightarrow c  = \dfrac{2}{3}\overrightarrow a  + \dfrac{5}{9}\overrightarrow b \)

\(A'\left( { - 1;0} \right)\)

\(B'\left( {9;0} \right)\)

\(C'\left( {2;7} \right)\)

 Hai tam giác \(ABC\) và \(A'B'C'\) có cùng trọng tâm

$O\left( {3; - \dfrac{7}{2}} \right)$ 

$O\left( {2; - \dfrac{5}{2}} \right)$

$O\left( { - 2; - \dfrac{5}{2}} \right)$

$O\left( {2;\dfrac{5}{2}} \right)$

\(G\left( { - \dfrac{2}{3};\dfrac{2}{3}} \right)\)

\(G\left( { - \dfrac{2}{3};\dfrac{1}{3}} \right)\)

\(G\left( { - \dfrac{1}{3};\dfrac{1}{3}} \right)\)

\(G\left( {\dfrac{2}{3};\dfrac{1}{3}} \right)\)