Can you help me solve this system of equations?

Question

Update: A tomato company wants to purchase a fleet of 20 covered hopper trailers with a capacity of 216,000 cubic feet. Hoppers with 3 different carrying capacitys are available. 6000CF, 9000CF, and 12000CF. how many of each type of trailer should he lease?

1) how many variables are there? List them
2)give the system of equations
(i got 6000x+9000y+12000z=216000

Answer 1

You have assigned the following variables correctly as...

x=6000cf hopper

y=9000cf hopper

z=12,000cf hopper

 

So there are 3 variables total as you have listed in answer to Q1.

 

Your equation is also correct...

6000x+9000y+12000z=216000...Eq1

 

...and the 2nd equation can be written as...

x+y+z=20....Eq2, total number of hoppers, given, in answer to Q2.