Algebra 3 Lesson 1.6 Objective: SSBAT write equations that model real life data. Standards: M11.A.2.2.1, M11.D and M11.D.3.2.3

Warm-Up 1.6 Write an equation for each given the slope & y-intercept. 1.m = 3 and b = -4 2.m = ¾ and b = 8 3.m = - ½ and b = 20 4.m = -7 and b = 15.5

Writing a Linear Equation for a Real Life Application  Slope (m) = Rate of Change  Y-intercept (b) = Initial Value, Starting Amount, Original Amount, Base Pay, etc.

1. You buy a house for $125,000 and it is expected to increase in value at the rate of $4,000 per year. Write an equation describing the value of the house (y) in terms of the number of years (x). Beginning value = $125,000 Rate of change = $4,000 per year.

2. You buy an automobile for $23,000 and it is expected to depreciate in value at the rate of $2,400 per year. Write an equation describing the value of the car (y) in terms of the number of years (x). Beginning value = $23,000 Rate of change = – $2,400 per year.

3.Joe is paid $800 a month plus 15% of his sales. a) Write an equation to represent Joe’s earnings, y, for x dollars of sales. b) Find Joe’s earnings (y) if he has $10,000 in sales for a month a) Base Pay = 800 Rate = 15% .15 y =.15x + 800

3.Joe is paid $800 a month plus 15% of his sales. a) Write an equation to represent Joe’s earnings, y, for x dollars of sales. b) Find Joe’s earnings (y) if he has $10,000 in sales for a month b) Let x = and solve for y y =.15(10000) y = $2300  He would make $2300 for that month if he had $10000 in sales.

4.You can rent a car from Company A for $49 a day plus $0.10 a mile. a) Write an equation to represent the total cost, y, to rent a car for x number of miles. b) Find the cost to rent a car for a day if you are to travel 65 miles that day. a)m = 0.10 and b = 49 y = 0.10x + 49 b)Let x = 65 y = 0.10(65) + 49 y = $55.50

5.A plane starts its descent at 34,500 feet. It will descend at a constant rate, which is 1500 feet per minute. a) Write an equation to show the planes altitude, y, after descending x number of minutes. b) Find the height of the plane after 12 minutes c) Find how long it will take the plane to land a)m = and b= y = -1500x b)Let x = 12  y = -1500(12) y = feet c) Let y = 0  0 = -1500x x = x = 23 minutes

Complete Worksheet 1.6