47.0k views
2 votes
Let u = <-5, 1>, v = <7, -4>. find 9u-6v.

a. <18, 18>
b. <-87, 33>
c. <-36, -18>
d. <-3, -15>

2 Answers

4 votes
B. Is the correct answer

-Hope this helps you!
User Dasser Basyouni
by
7.1k points
4 votes
Answer:
b. <-87,33>

Step-by-step explanation:
We are given that:
u = <-5,1>
v = <7,-4>

We want to get 9u-6v
First we will calculate the 9u and 6v separately and then subtract the 6v from the 9u as follows:
9u = 9*<-5,1> = <9*-5 , 9*1> = <-45,9>
6v = 6*<7,-4> = <6*7 , 6*-4> = <42,-24>
Finally:
9u - 6v = <-45,9> - <42,-24> = <-45-42 , 9--24> = <-87,33>

Hope this helps :)
User Alesch
by
7.2k points