Warm Ups {(2,0) (-1,3) (2,4)} 1. Write as table 2. Write as graph 3. Write as map 4. State domain & range 5. State the inverse
5-3 Equations as Relations Objective: To determine solutions to equations. Standard 16.0
Ordered pairs: always write in alphabetical order (x, y) (a, b) (r, s) Linear Equation: an equation that, when graphed, creates a straight line. Solution: ordered pairs that give a true statement
Example 1 Which of these are solutions of 3x + y = 8 ? 1. Plug in the values for x and y 2. Simplify each side 3. Check if they are equal (4,-4) (8,0)(2,2)(3,1) x y 3(4) + (-4) = = 8 8 = 8 Yes! x y 3(8) + 0 = = 8 24 = 8 No! x y 3(2) + 2 = = 8 8 = 8 Yes! x y 3(3) + 1 = = 8 10 = 8 No!
Example 2 Solve the equation 2x + 2y = 14 given x = Substitute 2. Solve for remaining variable 3. Write as ordered pair 2x + 2y = 14 2(-3) + 2y = y = y = 20 y = 10 (-3, 10)
Given the domain… Solve the equation x + y = 4 if the domain is {-4, -2, 0, 2, 4} Plug it in, domain = x Answer as ordered pairs!
What if… I gave you the range instead of the domain? How would you solve the equation given the range? Plug the values in for y, then solve for x
Example 3 Make a table and graph y = x + 6 if the domain is {-4,-3,2,4} Answer: (-4,2) (-3,3) (2,8) (4,10) This is a linear equation so you should be able to connect the dots and make a line.
TOO 1. y = -1 for 3x = 13 – 2y 2. x = 10 for 5x + 3 = y Answers 1. (5, -1) 2. (10, 53)
Homework 5-3 Practice