Question

Se u= ( 3,a+5,10) e v= ( b+4,2,20) sao vetores de R³ linearmente dependentes (KD);, então s= 4u - 2v é igual a:

Answer 1

linearmente dependentes (LD)

(3,a+5,10) = k*(b+4,2,20)

3=k*(b+4) ==> 3=b/2 +2 ==> b=2

a+5=2k ==> a=-4

10=k*20 ==>k=1/2

s =4*(3,-1,10)-2*(6,2,20)

s=(12,-4,40)-(12,4,40)

s=(0 , 0 ,0)