Grade 9 MATH Term 1 Week 6: Solving Problems Involving Linear Functions | MATATAG Q1 Tagalog

Summary

Key Points

• Linear relationships involve a constant rate of change and can be expressed through verbal statements, tables, graphs, and algebraic equations. 1:11
• To form the equation, the constant term (b) represents the base fee and the slope (m) represents the per‑kilometer charge. 1:39
• The jeep fare example shows a base fee of 17 pesos for the first 4 km and an additional 230 pesos per extra kilometer, leading to the equation y = 230x + 17 where x counts kilometers beyond the initial 4. 1:50
• A worker earning 400 pesos per day is modeled by y = 400x, with x as days worked and y as total earnings. 8:24
• A bicycle traveling at a constant speed of 12 km/h is represented by y = 12x, where x is time in hours and y is distance traveled. 8:53
• A laundry service charging a fixed 30‑peso fee plus 45 pesos per kilogram yields the equation y = 45x + 30, with x as kilograms of laundry. 10:29
• A printing shop with a 15‑peso layout fee and 3 pesos per page uses the equation y = 3x + 15, where x is the number of pages printed. 13:55
• The video solves a fare problem for a 9‑km trip by substituting x = 5 into y = 230x + 17, resulting in a total cost of 2,850 pesos. 18:15
• It calculates revenue for selling 24 bottles of water at 15 pesos each using y = 15x, giving a total of 360 pesos. 18:50
• Finally, it demonstrates earnings calculations for a student working 12 hours at 120 pesos per hour (y = 120x = 1,440 pesos) and a salesperson with a 10,000‑peso salary plus 500‑peso commissions for 8 sales (y = 500x + 10,000 = 14,000 pesos). 23:26