Question 983941
If you are comfortable with the basic algebra needed, then the example problem is best understood
rate of doing work.
People working on the same job together do the work according to the sum of their individual rates.

Rate of wood chopping multiplied by time of wood chopping becomes amount of wood chopped.
RT=W to relate rate, time, and amount of wood or amount of Work.


The example gives two descriptions.
Assign some variables, but being done with different names than your example steps are showing.
r, the rate for one wood-chopper in unit of CORD/HOUR
Time will be in HOUR unit
WORK will be in CORD unit  ("cords of wood").


8 men, 9 cords, 6 hours:
{{{8r*6=9}}}


4 men, 3 cords, how much time:
We need another variable, ...
Let t be the time in hours which we want to solve.
{{{4r*t=3}}}


We formed two equations making a system of equations.
{{{highlight_green(system(8r*6=9,4r*t=3))}}}


This can be solved for each of the two variables, r and t.
CAN YOU solve this system?
Solve the first equation for r.
Use what you find for r in the other equation and solve for t.