Question

Let u = <7, -3>, v = <-9, 5>. Find 4u - 3v.

Answer 1

that'd be just plain addition of vectors

Answer 2

I didnt read about that :/

Answer 3

8, -6?

Answer 4

a * < b, c> => < a*b, a*c> # scalar multiplication

<b , c > + <d, e> => <b+d, c+e> # addition

Answer 5

I'm sorry I dont understnad

Answer 6

4u => 4 < 7, -3 > # scalar multiplication

Answer 7

ok...so gimme a sec
please

Answer 8

i got 1, 12...thats not right

Answer 9

you have 4u - 3v
so you do the "scalar multiplication" first
then do the "vector addition" operation on the products

Answer 10

...ill try again...

Answer 11

i dont get it...4(7,3) -3(-9,5)

Answer 12

is the answer then 55, -27

Answer 13

\(\large \begin{matrix}
a \times <b, c> &\implies & < a \times b, a\times c> &\textit{ scalar multiplication}\\
<b , c > + <d, e> & \implies & <b+d, c+e> &\textit{vector addition}
\end{matrix}\)

Answer 14

where did d and e come from :(

Answer 15

hehe, it's just a notation for the operations

Answer 16

:((((

Answer 17

that's how you'd multiply a scalar
that's how you'd add 2 vectors

Answer 18

It doesnt make sense

Answer 19

\( \begin{matrix}
\color{red}{a} \times <b, c> &\implies & < \color{red}{a} \times b, \color{red}{a}\times c> &\textit{ scalar multiplication}\\
<\color{blue}{b} ,\color{blue}{ c} > + <\color{green}{d}, \color{green}{e}> & \implies & <\color{blue}{b}+\color{green}{d}, \color{blue}{c}+\color{green}{e}> &\textit{vector addition}
\end{matrix}\)

see it now?

Answer 20

no

Answer 21

http://www.youtube.com/watch?v=pNMrYACjHXQ

Answer 22

so i just need the botton formula you keep giving me

Answer 23

no

Answer 24

so the answer is 55, -27

Answer 25

right
?

Answer 26

hmm, I got something else, the -27 is correct though

Answer 27

that is the only answer possible...

Answer 28

28+27 = 55

Answer 29

Wanna help with another?

Answer 30

28 + (-27) => 1

Answer 31

please?

Answer 32

but its positive 27 becaise -9 and -3

Answer 33

ohhh nevermind, yes 55, I see what happened

Answer 34

:)

Answer 35

so wanna help again?

Answer 36

I can try

Answer 37

ok :) Let u = <-3, -5>, v = <-3, 1>. Find u + v

Answer 38

wait!

Answer 39

-6, -4 ???

Answer 40

yes

Answer 41

THANK YOUUUU

Answer 42

yw