10 points : )
once upon a time, a silver dollar contained $1 worth of silver. the sizes of other coins were based on the silver dollar; for example, a half dollar contained half the silver of a silver dollar.
use what you've learned about decimal numbers and fractions to write a paragraph explaining why the quarter coin is called a quarter.

So a quarter means 1/4th of anything. If a half dollar coin contained 1/2 the amount of silver from the original coin then by logic we can say a quarter coin would contain 1/4 of silver of the original coin. Therefore it's worth will be 1/4th of the 1$ coin which would be 1/4$ or 0.25$

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

step-by-step explanation:

your mom