Let u = {5,-12} and let c = -3. What is ll cu ll

Answer:
D) 39
Step-by-step explanation:
[tex]||\text{c}\bold{u}||=||3\langle5,12\rangle||=||\langle3*5,3*12\rangle||=||\langle15,36\rangle||=\sqrt{15^2+36^2}=\sqrt{225+1296}=\sqrt{1521}=39[/tex]