Question 1139504:  I think this is a system of equations question. 
 
A farmer plants soybeans, corn, and wheat and rotates the planting each year on his 500 acre farm. In a particular year, the profits from his crops were $120 per acre of soybeans, $100 per acre of corn, and $80 per acre of wheat. He plants twice as many acres of corn as soybeans.
 
How many acres did he plant with each crop the year he made a total profit of $51,000? 
 Answer by ikleyn(52898)      (Show Source): 
You can  put this solution on YOUR website! . 
 . 
 
 
A farmer plants soybeans, corn, and wheat and rotates the planting each year on his 500 acre farm.  
In a particular year, the profits from his crops were $120 per acre of soybeans, $100 per acre of corn, and $80 per acre of wheat.  
He plants twice as many acres of corn as soybeans.
 
 
How many acres did he plant with each crop the year he made a total profit of $51,000? 
~~~~~~~~~~~~~~~~~~
 
 
 
            This problem is to be solved using one equation in one single unknown.
 
 
 
Let x be the area for soybeans (in acres).
Then the area for corn is  (2x)  acres, and the area for wheat is the rest  (500-x-2x) = (500-3x) acres.
His total profit is then
    120x + 100*(2x) + 80*(500-3x) = 51000   dollars.
Simplify and solve for x
    120x + 200x + 40000 - 240x = 51000
    80x                        = 51000 - 40000
    80x                        = 11000
      x                        =   = 137.5
ANSWER.  137.5 acres for soybeans;  twice of it, 2*137.5 = 275 acres for corn,  and the rest, 500 - 137.5 - 275 = 87.5 acres for wheat.
 
Solved, explained and completed.
 
 
------------------
 
 
To see many other similar solved problems, look into the lesson
 
    - Advanced word problems to solve using a single linear equation
 
    - HOW TO algebreze and solve these problems using one equation in one unknown 
 
    - Challenging word problems to solve using a single linear equation 
 
in this site, and learn the subject from there.
 
 
 
=================
 
 
The major lesson to learn from my post is THIS :
 
 
    This problem is designed, is intended, and is expected to be solved using one equation in one single unknown.
 
 
Happy learning !
 
 
 
Do not forget to post me your "THANKS" after reading my post ! 
 
 
 
 
  | 
 
  
 
 |   
 
 |