Create Presentation
Download Presentation

Download Presentation
## 6.2 Solving Systems by Substitution

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**6.2 Solving Systems by Substitution**Objectives: Solve systems of linear equations in two variables by substitution.**Example 1: Solve for x when –**A. B. C. D.**Why is graphing not always the most useful way to solve a**system of equations? • We don’t always land on whole numbers! • Remember – when solving a system of linear equations we are looking for an ordered pair that makes both equations true. • We will use substitution when: • Both equations are solved for 1 variable. • 1 equation is solved for a variable, and one is in standard form.**Example 2: continued...**C. D.**Homework**• Page 347: 1, 2, 8-11**Example 3: Josie is deciding between two cell phone plans.**The first plan has a $50 sign-up fee and costs $20 a month. The second plan has a $30 sign-up fee and costs $25 a month. • After how many months will the total cost be the same? • What will the cost be? • If Josie has to sign up for a one year contract, which plan would be cheaper?**Trivia**1. Which TV show has the judges: Mariah Carey, Nicki Minaj, Randy Jackson, & Keith Urban? American Idol 2. Which Disney movie has the characters: Prince Eric, Sebastian, Flounder, Ursula, and King Triton? Little Mermaid**If both equations are in standard form:**You must solve one of them for a variable and then substitute.**Practice:**• Practice 6.2 WS**Homework**• Page 347: 8-23 odd