Question

I've tried almost everything with this question, but
I can't figure it out. I really need help solving it. Can you also tell me how you solved it? There are more just like it.

Answer 1

if vector u = <3,5> then what is vector -4*u equal to?

Answer 2

-23.3236?

Answer 3

I don't know how you're getting that. You just multiply each coordinate by -4

u = <3,5>
-4*u = -4*<3,5>
-4*u = <-4*3,-4*5>
-4*u = <-12,-20>

make sense?

Answer 4

oh. makes sense. what do I do next?
(-12, -20) *(-8, 8)

Answer 5

now we dot product those vectors together

the dot product is where we multiply the corresponding coordinates and then add up the products