Amy and Brad each have some money. Carly has no money.
Amy gives £7 to Carly.
Brad gives £5 to Carly.
Now they all have the same amount of money.
How much money did Amy have to begin with?

Step-by-step explanation:

carly had nothing, amount of money = £0

amy gave her £7 and brad gave her £5,

carly now has £5 and £7

amount of money of carly= £7 + £5

= £12

you are told that they all have the same amount of money and you know that carly has £12. so:

amy has £12, brad has £12 too.

If amy has £ 12 now after giving away £7, then: let x be the initial amount of money amy had,

x - 7 = 12

x = 12 + 7

x = 19

thus, amy had £19.

have a beautiful day/night!

-s.

$35.59 in pounds

step-by-step explanation:

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