Question

Let u = <-5, -9>, v = <6, 8>. Find -8u - 2v. please help :(

Answer 1

its just multiplication and addition

Answer 2

what do I multiply and add? Is there a formula?

Answer 3

u = <-5, -9>
v = < 6, 8>


-8u = <-5(-8), -9(-8)>
-2v = < 6(-2), 8(-2)>


-8u = < 40, 72 >
-2v = <-12, -16 >
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? , ?

Answer 4

there is another notation if its simpler to see:

u = <-5, -9> = -5x -9y
v = < 6, 8> = 6x +8y


-8u =-8(-5x -9y)
-2v = -2(6x +8y)


-8u = 40x + 72y
-2v = -12x -16y


-8u -2v = 40x + 72y -12x -16y

and combine like terms

Answer 5

Ahh okay I get it so my answer would be <28,56>??

Answer 6

yes

Answer 7

Thank you so much

Answer 8

youre welcome