Question

Dado os vetores u = (-5,2,3) e v = (-2, -1, -1),determine u + 3v:
Escolha uma:
A-( -1, 11,0 )
B-( 11,1,0 )
C-( -11,-1,0 )
D-(-11,-1,1 )

Answer 1

u+3(-2,-1,-1)
u+(-6,-3,-3)
(-5,2,3)+(-6,-3,-3)= (-11,-1,0)
Letra C

Answer 2

Dados os vetores

$\mathbf{u}=(-5;\,2;\,3)\;\;\text{ e }\;\;\mathbf{v}=(-2;\,-1;\,-1),$

encontrar

$\mathbf{u}+3\mathbf{v}:$


$\mathbf{u}+3\mathbf{v}=(-5;\,2;\,3)+3\,(-2;\,-1;\,1)\\ \\ \mathbf{u}+3\mathbf{v}=(-5;\,2;\,3)+(3\cdot (-2);\,3\cdot (-1);\,3\cdot (-1))\\ \\ \mathbf{u}+3\mathbf{v}=(-5;\,2;\,3)+(-6;\,-3;\,-3)\\ \\ \mathbf{u}+3\mathbf{v}=(-5-6;\,2-3;\,3-3)\\ \\ \boxed{\begin{array}{c}\mathbf{u}+3\mathbf{v}=(-11;\,-1;\,0) \end{array}}$


Resposta: alternativa $\text{c) }(-11;\,-1;\,0).$