MathematicsClass 7Simple Equations
Applications to Practical Problems
Using linear equations with one variable to solve puzzle-like word problems.
Class 7 · MathematicsCBSE & ICSE SOF IMO IOQM
Definition
Applications to practical problems involve using simple equations to solve real-life word scenarios. This process requires carefully reading the problem, assigning a variable to the unknown quantity, setting up the correct equation, solving it, and verifying the answer in the context of the problem.
Worked examples
1
A number increased by 12 is 30. Let the number be x, so x + 12 = 30, which gives x = 18.
2
Mother's age is 3 times her daughter's age. If the mother is 45, let daughter's age be y, so 3y = 45, giving y = 15 years.
3
The length of a rectangular garden is 5 meters more than its breadth. If the perimeter is 30 meters, set up 2(l + b) = 30 where l = b + 5 to find the dimensions.
Common mistakes
- • Failing to define the variable clearly at the beginning of the solution.
- • Stopping the solution as soon as the variable value is found without checking if it makes sense in the real-world context.