You would average 52 words a minute.
8580 / 165 (60 + 60 + 45) = 52
To subtract vectors, you simply have to subtract correspondent coordinates.
So, if you have

the subtraction is simply

So, in your case, we have

The share of Natasha is £ 42
<em><u>Solution:</u></em>
£70 is divided between Natasha, Richard & Stephen
Total amount = 70
Let the share of natasha be "x"
Let the share of richard be "y"
Let the share of stephen be "z"
Natasha gets twice as much as Richard
x = 2y ------ eqn 1
Richard gets three times as much as Stephen
y = 3z
----- eqn 2
Total amount = 70
share of natasha + share of richard + share of stephen = 70
x + y + z = 70
Substitute eqn 1 and eqn 2

Substitute y = 21 in eqn 1
x = 2y = 2(21) = 42
x = 42
Thus natasha gets £ 42
F(x) = 4 - x² g(x) = 6x
(g - f)(x) = g(x) - f(x)
(g - f)(3) = g(3) - f(3)
g(x) = 6x
g(3) = 6*3 = 18
f(x) = 4 - x²
f(3) = 4 - 3² = 4 - 9 = -5
(g - f)(3) = g(3) - f(3) = 18 - (-5) = 18 + 5 = 23
(g - f)(3) = 23