Recall that:
[tex]\begin{gathered} \cdot=xv+yw, \\ a=. \end{gathered}[/tex]
Then:
[tex]\begin{gathered} u\cdot v=0*5+(-7_)*(-8)=0+56 \\ =56. \end{gathered}[/tex]
Then:
[tex](u\cdot v)4v=56*4<5,-8>.[/tex]
Simplifying the above result we get:
[tex]\begin{gathered} 56*4<5,-8>=224<5,-8>=<224*5,224*(-8)> \\ =<1120,-1792>. \end{gathered}[/tex]
Answer:
[tex]\begin{equation*} <1120,-1792>. \end{equation*}[/tex]
