Writing Equations from Graphs in Slope-Intercept Form

This video tutorial teaches how to write equations from graphs by identifying the slope and y-intercept. It begins with a review of the general equation of a line, y = mx + b, explaining the meaning of 'm' as the slope and 'b' as the y-intercept. The tutorial provides step-by-step instructions on finding the slope as 'rise over run' and identifying the y-intercept where the line crosses the y-axis. Several examples are given, demonstrating how to write equations for different lines, including those with positive and negative slopes. The video concludes with advanced examples and encourages practice by adding dots to graphs and finding equations.

What is the general form of a linear equation?

• x = my + b

• y = mx^2 + b

• y = m/x + b

• y = mx + c

Tags

TEKS.MATH.8.5A

TEKS.MATH.8.5B

TEKS.MATH.8.5I

What does the 'm' in the linear equation represent?

• X-intercept

• Slope

• Y-intercept

• Maximum value

Tags

TEKS.MATH.8.4B

How is the slope of a line calculated?

• Run over rise

• Rise over run

• Y-intercept over X-intercept

• X-intercept over Y-intercept

Tags

TEKS.MATH.A.3C

If a line crosses the y-axis at 2, what is the y-intercept?

• 2

• -2

• 1/2

• 2x

Tags

TEKS.MATH.8.5A

TEKS.MATH.8.5B

TEKS.MATH.8.5I

For a line with a slope of 1/2 and y-intercept 2, what is the equation?

• y = 2/x + 1

• y = 2x + 1/2

• y = 1/2x + 2

• y = x/2 + 2

Tags

TEKS.MATH.8.5A

TEKS.MATH.8.5B

TEKS.MATH.8.5I

What is the equation of a line with a slope of -3/4 and y-intercept 4?

• y = 4x - 3/4

• y = 3/4x - 4

• y = -3/4x + 4

• y = -4x + 3/4

Tags

TEKS.MATH.A.2C

How do you write the equation of a line with no predefined points?

• Guess the slope and intercept

• Plot any two points and calculate

• Use the slope formula and estimate the intercept

• It's not possible

Tags

TEKS.MATH.8.5A

TEKS.MATH.8.5B

TEKS.MATH.8.5I

What is the equation for a line with a slope of 5 and a y-intercept of -3?

• y = 5x - 3

• y = -3x + 5

• y = 5x + 3

• y = -5x - 3

Tags

TEKS.MATH.8.5A

TEKS.MATH.8.5B

TEKS.MATH.8.5I

If a line's equation is y = -2x, what is the y-intercept?

• 2

• 0

• There is no y-intercept

• -2

Tags

TEKS.MATH.8.4B

What does a negative slope indicate about the direction of a line?

• It is vertical

• It is horizontal

• It falls from left to right

• It rises from left to right

Tags

TEKS.MATH.8.4B