Please help!! Use the given vectors to find the indicated quantities.
u =(5, - 2), v =(0, 1), w =(-1, -3)
(a) (u • v)w (b) 5u • V

Part (a)

Lets say we had the two general vectors

u = (a,b)

v = (c,d)

The dot product is

u dot v = a*c + b*d

Apply that rule to these specific vectors

u = (5, -2)

v = (0, 1)

So we get

u dot v = 5*0 + (-2)*1

u dot v = 0 - 2

u dot v = -2

Therefore,

(u dot v)*w = -2*(-1, -3)

(u dot v)*w = ( -2*(-1), -2(-3) )

(u dot v)*w = (2, 6)

 (2, 6)

Part (b)

u = (5, -2)

5u = 5*(5, -2)

5u = (5*5, 5*(-2))

5u = (25, -10)

5u dot v = (25, -10) dot (0,1)

5u dot v = 25*0 + (-10)*1

5u dot v = 0 - 10

5u dot v = -10

-10

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations:

answer: c

(2, -4)

goes 7 to the

(9, 4)

easy