Linear equations are used in various day-to-day examples, such as:
1. _Cost calculation_: Total cost = number of items × price per item (e.g., 3 shirts × $20 = $60)
2. _Distance and time_: Distance = speed × time (e.g., 60 miles/hour × 2 hours = 120 miles)
3. _Budgeting_: Total expenses = fixed costs + variable costs (e.g., rent + utilities + groceries)
4. _Cooking recipes_: Ingredient quantity = serving size × number of servings (e.g., 2 cups flour × 4 servings = 8 cups)
5. _Travel planning_: Total travel time = driving time + waiting time (e.g., 2 hours driving + 1 hour waiting = 3 hours)
6. _Shopping discounts_: Sale price = original price - discount (e.g., $50 - 20% discount = $40)
7. _Health and fitness_: Calories burned = exercise duration × intensity (e.g., 30 minutes × high intensity = 200 calories)
8. _Personal finance_: Total savings = monthly savings × number of months (e.g., $500 × 6 months = $3000)
9. _Home improvement_: Total cost = material cost + labor cost (e.g., $1000 materials + $2000 labor = $3000)
10. _Environmental impact_: Carbon footprint = energy consumption × emissions rate (e.g., 1000 kWh × 0.5 kg CO2/kWh = 500 kg CO2)
These examples illustrate how linear equations help us solve everyday problems and make informed decisions.