Ailey is shopping at a department store during a 20% off everything sale. She also has a coupon for $5.00 off the sale amount. Hailey wants to keep her total under $65.00 before tax, so she creates this inequality: 0.80x − $5.00 ≤ $65.00.

Which inequality represents all possible solutions for x?

A.
x ≤ $75.00
B.
x ≤ $76.25
C.
x ≤ $86.25
D.
x ≤ $87.50

86.25

Step-by-step explanation:

86.25 x .80 = 69.20

69.20 - 5.00 = 64.20 which is under 65.00

answer d is incorrect because she would be at 65.00 and she wants to be under 65.00

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