Joanna purchased four boxes of cookies for a party. Each box cost $3.28, including tax. PLEASE HELP Which expression represents how to calculate the total cost of the cookies Joanna purchased? 4 ÷ $3.28
4 – $3.28
4($3.28)
4 + $3.28

a is ur answer

Step-by-step explanation:

4 / ($3.28)   is the correct answer

Step-by-step explanation:

As cost of  one box is  $3.28

the cost of four boxes will be  4 divided by the cost of one boxso that why the  4/($3.28) is correct option

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

5 x 14?

im new, sorry if this is wrong.

step-by-step explanation: