Grade 10 → Algebra → Linear Equations in Two Variables ↓
Application of Linear Equations in Word Problems
Linear equations in two variables are an important part of algebra that you learn in Class 10 Maths. These equations are important because they apply to real-world situations and help solve everyday problems. Understanding these equations can greatly enhance your problem-solving skills and logical thinking. This article will provide a comprehensive overview of how linear equations in two variables can be applied to word problems using simple language and many examples to aid understanding.
Understanding linear equations in two variables
A linear equation in two variables is generally of the form:
ax + by = c
Here, 'a'
, 'b'
and 'c'
are constants, while 'x'
and 'y'
are variables. This form of the equation when plotted graphically is a straight line.
The main goal in word problems is to form such equations using the given data and conditions, and then find the values of 'x'
and 'y'
by solving them.
How to develop equations from word problems
Understanding how to convert a problem into equations is an important step in solving word problems. Let's consider a general approach to converting word problems into linear equations:
- Read the problem carefully: Understand what is being asked. Identify the quantities involved and what you need to find out.
- Define variables: Assign symbols like
'x'
and'y'
to the unknown values you need to find. - Convert words into equations: Use the information provided to create an equation. Pay attention to key phrases that can help you identify mathematical operations.
- Solve equations: Use algebraic methods such as substitution or elimination to find the value of unknown values.
- Check your solution: Verify the solution by re-substituting the original conditions into the word problem.
Common scenarios in word problems
Solving linear equations using word problems can involve a variety of scenarios. Here are some common scenarios and how linear equations can be applied:
1. Age-related problems
Age-related problems usually involve relationships between the ages of different people. For example:
Example problem: Sally is two years older than twice the age of her brother John. If the sum of their ages is 22, how old is each of them?
Solution:
- Define the variables: Let
'x'
be John's age and'y'
be Sally's age. - Develop the equations: From the problem statement, we have the equations:
y = 2x + 2
x + y = 22
- Solve the equation:
Substitute y = 2x + 2 from the first equation into the second equation:
x + (2x + 2) = 22
3x + 2 = 22
3x = 20
x = 20/3
- Find y: Use the value of
'x'
to find'y'
:y = 2(20/3) + 2
y = 40/3 + 6/3
y = 46/3
Both excerpts show their correct ages. Be sure to verify the reasonableness of the answers based on your interpretation of the problem.
2. Mixing problems
These problems often involve finding the proportions of different substances in a mixture. Consider this example:
Example problem: A chemist needs to mix a 10% acid solution with a 50% acid solution to obtain 200 milliliters of a 30% acid solution. How much of each solution should he use?
Solution:
- Define the variables: Let's say
'x'
is the volume of the 10% solution and'y'
is the volume of the 50% solution. - Develop the equation:
x + y = 200
0.1x + 0.5y = 0.3(200)
- Solve the equation:
- Find y:
x = 100
Re-substitute:y = 200 - 100
y = 100
First equation gives: y = 200 - x
Substitute into the second equation:
0.1x + 0.5(200 - x) = 60
0.1x + 100 - 0.5x = 60
-0.4x = -40
x = 100
The chemist should use 100 ml of each solution.
Graphical representation
Visualization can be of great help in understanding the solution of linear equations. Let us present a graphical example:
This image shows the intersection of these lines that represent x = 3
and y = 2
when plotted as ax + by = c
. The intersection represents the solution to both linear equations.
Conclusion
Linear equations in two variables have many applications when it comes to solving word problems. Understanding the formation of equations based on problem statements, translating them into visual or graphical representations, and solving them to find the required solutions are key components of the grade 10 math curriculum. Getting familiar with exercises and varied examples is helpful in mastering these skills.
The problems and examples discussed here serve as a basic foundation for understanding the practical utility of algebraic concepts in real-world scenarios. By mastering these techniques, you can move from solving abstract equations to understanding concrete situations.