$14.04
1st you take 19.5 and multiply it by 0.28 which is 5.46
Then take 19.5 and subtract 5.46
$14.04 is your final answer
We need to solve the following system by substituition:

To solve by substituition means that we need to isolate one variable in one of the equations and replace one expression with the other. This is done below:

Then we need to replace the value of "x" in any of the two equations.

The solution is (-3,-5).
Answer:
Possible lengths of the silk fibre 'x' are 100, 75, 60, 50 and 30 yards respectively.
Step-by-step explanation:
Let the length of the silk fiber = x yards.
Let the number of silk fibres = a.
It is given that the silk fibers between 3 to 10 yards are combined to form a silk thread of 300 yards.
So, we get the equation,
, where 
i.e.
, 
So, the possible values of 'a' are 3, 4, 5, 6 an 10.
Thus, the possible lengths of the silk fibre 'x' are 100, 75, 60, 50 and 30 yards respectively.
Solve for a.
6 = a / 4 + 2
Subtract 2 from both sides.
4 = a / 4
Multiply both sides by 4.
16 = a
Hope this helps!