Transcript Day Problems • Use the slope and y-intercept to graph each equation. 1.
Day Problems • Use the slope and y-intercept to graph each equation.
1. y = 2 – 3x 2. y = 2x + 5 3.
y
3 4
x
1 4.
y
1 2
x
3
• 6.3 Standard Form • Standard Form of a Linear Equation – The
standard form of a linear equation
is Ax + By = C, where A, B, and C are real numbers, and A and B are both not zero.
x – intercept –
the x-coordinate of the point where a line crosses the x-axis.
• To graph a linear equation in standard form, you can find the x-intercept by substituting 0 for y and solving for x.
• To find the y-intercept, substitute 0 for x and solve for y.
Finding x- and y-intercepts • Find the x- and y-intercept of 3x + 4y = 8. • Step 1 – to find the x-intercept, substitute 0 for y and solve for x.
3
x
4
y
8
3
x
3
x
8
x
8 3 • So, the x-intercept is 8 .
3
Finding x- and y-intercepts • Find the x- and y-intercept of 3x + 4y = 8. • Step 2 – to find the y-intercept, substitute 0 for x and solve for y.
3
x
4
y
8 4
y y
8
8
y
2 • So, the y-intercept is 2.
Graphing Lines Using Intercepts • Graph 2x + 3y = 12 using intercepts.
• Step 1 – Find the intercepts 2
x
3
y
12 Step 2 – Plot (6,0) 2
x
3(0) 12 and (0,4). Draw a line through the points.
2
x x
12 6
(0 , 4) (6 , 0)
2(0) 3
y
12 3
y y
12 4
Graphing Horizontal and Vertical Lines a. Graph y = -3.
b. Graph x = 2.
• Day Problems 2/9/11 Find the x- and y-intercepts of each equation.
1. x + 2y = 18 2. 3x – y = 9 3. -5x + y = 30 • Graph each equation using x- and y intercepts.
4. x + y = 2 5. -3x + y = 6
Transforming to Standard Form 2/9/11 • Write
y
3 4
x
2 in standard form using integers.
y
4 4
y
y
3 4
x
4 3 2 3 4
x x
4
y x
8 8 2
• Write the Equation in Standard Form
Write the equation in standard form using integers.
a. y = 3x + 1 -3x + y = 1 b.
y
1 2
x
4 2
y
8 2
y
8
More Practice!!!
• Textbook – p. 301 #2 – 32 even.
• Homework – Worksheet 6.3