First, we convert it into a unit like this
20 workers × 30 days = 600 units work
After leaving the 5 workers, we have 35 days to complete the work.
In 35 days only 15 workers will do the work.
So the work completed in 35 days by 15 workers = 35 ×15 =525 units
Remaining unit = 600 -525 =75 units
This unit would do by 5 workers in (75/5) = 15 days.
So after 15 days, 5 workers should leave the job.
12. I need the graphs to answer it
11. y = 1/2x - 1
10. The first graph is the best
1.
The edge lengths of a triangle are inversely proportional to 2,3 and 4.
The actual proportions of the lengths are then
12(1/2:1/3:1/4)=6:4:3
The longest side
= 39* (6/(6+4+3)
= 39*6/13
=18
2. 63 breads : 35 kg flour
is the same as
54 breads : x kg flour
Cross multiply and get
x=54*35/63=30
30 kg of flour are needed to make 54 breads.
For any equation,
assume solution of a form, 
Which leads to,
Simplify to,
Then find solutions,
For non repeated real root y, we have a form of,
Following up,
For two non repeated complex roots 
where,
and,
the general solution has a form of,
Or in this case,
Now we just refine and get,
Hope this helps.
r3t40
Answer:
7(3 + 7)
Why:
7x3=21
7x7=49
