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

CCSS.8.EE.B.6

CCSS.8.F.A.3

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

• X-intercept

• Slope

• Y-intercept

• Maximum value

Tags

CCSS.8.EE.B.5

How is the slope of a line calculated?

• Run over rise

• Rise over run

• Y-intercept over X-intercept

• X-intercept over Y-intercept

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

• 2

• -2

• 1/2

• 2x

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

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

CCSS.8.EE.B.6

CCSS.8.F.A.3

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

CCSS.8.F.B.4

CCSS.HSF.LE.A.2

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

CCSS.8.EE.B.6

CCSS.8.F.A.3

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

CCSS.8.EE.B.6

CCSS.8.F.A.3

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

• 2

• 0

• There is no y-intercept

• -2

Tags

CCSS.8.EE.B.5

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

CCSS.8.EE.B.5