I need help with c please.

Answer:
||w|| = 6
Step-by-step explanation:
||w|| = modulus or magnitude of vector w
Since formula to get the modulus of any vector = [tex]\sqrt{\text{(x-component)}^2+\text{(y-component)}^2}[/tex]
Vector w = <-6, 0>
x-component of vector w = (-6)
y-component of vector w = 0
Therefore, ||w|| = [tex]\sqrt{(-6)^2)+(0)^2}[/tex]
= 6