1. 3.4 Standard form

2. What We Will Learn Graph horizontal and vertical lines
Graph standard form using intercepts
Story problems

3. Needed Vocab Standard form: Ax + By = C
X- intercept: where graph crosses the x-axis
Y-intercept: where graph crosses the y-axis

4. Ex. 1 Horizontal and Vertical Lines
𝑦=𝑐
C is any number
Horizontal line
Graph 𝑦=4
𝑥=𝑐
C is any number
Vertical line
Graph 𝑥=−2

5. Ex. 2 Using Intercepts to Graph
Use when in standard form
Ax + By = c
Graph 3x + 4y = 12
x-intercept:
3𝑥+4 0 =12
3𝑥=12
3𝑥 3 = 12 3
𝑥=4
y-intercept:
3 0 +4𝑦=12
4𝑦=12
4𝑦 4 = 12 4
𝑦=3
Steps
1. Find x-intercept
Plug in 0 for y
Plot x-intercept
2. Find y-intercept
Plug in 0 for x
Plot y-intercept
3. Connect the dots

6. Your Practice Graph 5𝑥+3𝑦=30 x-intercept: 5𝑥+3 0 =30 5𝑥=30 5𝑥 5 = 30 5
𝑥=6
y-intercept:
5 0 +3𝑦=30
3𝑦=30
3𝑦 3 = 30 3
𝑦=10

7. Ex. 3 Story Problems
You are planning an awards banquet for you school. You need to rent tables to seat 180 people. Tables come in two sizes. Small tables seat 6 people, and large tables seat 10 people. Write an equation and graph the equation. Find four possible combinations.
6𝑥+10𝑦=180
Do same as example 2
6𝑥+10 0 =180
6𝑥=180
6𝑥 6 = 180 6
𝑥=30
𝑦=180
10𝑦=180
10𝑦 10 =
𝑦=18