The percentage would be 75% that carpenters that showed up for work
because when dividing 200 x 4 you will get 50 and 50 would equal to 25% of the total of carpenters and if you multiply 50 by 3 would get 150 and a percentage wise that would be 25% times three which is 75 and that’s how you get the answer
Since the total is 42 divide by two since they are the same length so it would be 21
Answer:

Step-by-step explanation:
The given system is:


Since I prefer to use smaller numbers I'm going to divide both sides of the first equation by 3 and both sides of the equation equation by 6.
This gives me the system:


We could solve the first equation for
and replace the second
with that.
Let's do that.

Subtract
on both sides:

So we are replacing the second
in the second equation with
which gives us:





Now recall the first equation we arranged so that
was the subject. I'm referring to
.
We can now find
given that
using the equation
.
Let's do that.
with
:



So the solution is (8,-1).
We can check this point by plugging it into both equations.
If both equations render true for that point, then we have verify the solution.
Let's try it.
with
:


is a true equation so the "solution" looks promising still.
with
:


is also true so the solution has been verified since both equations render true for that point.
The coordinate (2,20) indicates that he rode 20 miles in 2 hours