Verbal Problem Solving With a System of Linear Equations

To solve verbal problems with systems of linear equations we will construct the system of equations based on the text of the problem.

  • We will start by pointing out what we are asked to solve for in the unknowns X X and Y Y .
  • Based on the conditions met by X X and Y Y in the verbal problem we will write down the relevant equations with the corresponding numbers and unknowns.
  • After drawing the equations appropriate to the problem, we can solve them in the algebraic way: through the substitution method or the equalization method, in this way we will solve for the two unknowns.

Example of Solving Word Problems with a System of Linear Equations

The price of 3 3 chocolates and 3 3 snacks is 45 45 $.
The price of 8 8 chocolates equals the price of 16 16 sandwiches.
What is the price of the chocolate and the sandwich?
We will indicate what we are asked to find with the unknowns X X and Y Y :
X= X= Price of the chocolate
Y= Y= Price of the snack

We will make the equations according to the conditions stated in the problem:
In fact, we will translate the text to equation and we will do it on the basis of what is written.

A - Verbal problem solving with a system of linear equations

We will solve the system of equations in the way that is most comfortable for us. Here we will use the substitution method and isolate the X X .
x=2yx=2y
We will substitute it into the first equation and find the : We will place it in the equation that is most convenient for us to find the : And from here we will give the verbal answer like this: The price of the chocolate is $ and the price of the snack is $. Y Y
3×2y+3y=453 \times 2y+3y=45
6y+3y=456y+3y=45
9y=459y=45
y=5y=5
X X
x=2×5x=2 \times 5
X=10X=10
10 10 5 5


Join Over 30,000 Students Excelling in Math!
Endless Practice, Expert Guidance - Elevate Your Math Skills Today