19) Jason received an Amazon gift card for his birthday. After he buys a song, the card's value is $17.21. After he purchases a second song, the card is worth $14.42. Jason downloads one more song and has $11.63 left on the card. i) Write an equation to define a as the amount of money left on the gift card after n purchases. ii) Jason plans to download a song every Tuesday moming. How many weeks in a row can he buy a song before the gift card runs out?​

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12

no

step-by-step explanation:

correct choice is a

step-by-step explanation:

the equation of the line passing through the points and is

thus, the equation of the line that passes through the points (0, -6) and (-3, 0) is