They need to park the Mystery Machine.  They could either park in the lot that charges $5 and then $2 an hour, or they could park using the meter on the street that charges $3.75 per hour.  Write an equation that describes when the cost is the same at both locations (the parking lot and on the street).
Please, I just need an equation

5 + 2x = 3.75x

Step-by-step explanation:

From the question, they could either park in the lot that charges $5 and then $2 an hour, or they could park using the meter on the street that charges $3.75 per hour.

The equation that describes when the cost is the same at both locations goes thus:

Let the number of hours used be x

The equation can then be written as:

$5 + $2x = $3.75x

5 + 2x = 3.75x

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