Question

Dados os vetores u ⃗=(4a,-3b),v ⃗=(b,a) e w ⃗=(4,3). Determine o valor de 2a + b sabendo que:
u ⃗+3v ⃗=2w ⃗. (2,0 ponto)
a) 4
b) 8
c) 2
d) 10
e) 6

Answer 1

$\left[\begin{array}{c}4a&-3b\end{array}\right] +3 \left[\begin{array}{c}b&a\end{array}\right] =2 \left[\begin{array}{c}4&3\end{array}\right]$

$\left[\begin{array}{c}4a&-3b\end{array}\right] + \left[\begin{array}{c}3b&3a\end{array}\right] = \left[\begin{array}{c}8&6\end{array}\right]$

$\left \{ {{4a+3b=8} \atop {3a-3b=6}} \right.$

$7a=14$
$a=2$

$b=0$

2(2)+0=4

"a"