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write the equation of a line from a graph - Printable Mathematics Worksheets - Wayground

write the equation of a line from a graph

10 questions

8th - 8th Grade

Mathematics

This free Grade 8 mathematics worksheet helps students write equations of lines in slope-intercept form, y = mx + b, from graphs and given information. Across 10 multiple-choice questions, students identify the meaning of m and b, determine slope and y-intercept values from equations, classify a graph’s slope, and select equations that match graphed lines, including lines with fractional, positive, negative, and zero slopes. The worksheet also asks students to construct a slope-intercept equation when m and b are provided, reinforcing how each value appears in y = mx + b. It is useful for introducing or reviewing the connection between a line’s graph and its algebraic equation, while the answer choices help reveal whether students are confusing slope with y-intercept or mishandling signs and fractions. Use it for independent practice, a quick formative check, or review after direct instruction. The worksheet is available as a free printable PDF with a complete answer key.

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Worksheets

write the equation of a line from a graph

Total questions: 10

Name
Class
Date
1.
What letter represents the slope of a line in the equation y = mx + b?
a)
y
b)
m
c)
x
d)
b
2.
What does the "b" stand for in y=mx+b?
a)
slope
b)
x-intercept
c)
y-intercept
3.
Write the an equation for the graph shown.
a)
y = -2x + 2
b)
y = 2x + 2
c)
y = 1/2x- 2
d)
y = -1/2x + 2
4.
Write the equation of the line.
a)
y = -1/3x - 2
b)
y = 1/3x - 2
c)
y = 3x - 2
d)
y = -3x - 2
5.
What is the equation of the line?
a)
y = -3/4x + 3
b)
y = 4/5x + 3
c)
y = -4/5x + 3
d)
y = -4/5x
6.
What type of slope does the graph have?
a)
Zero
b)
Undefined
c)
Negative
d)
Positive
7.
What is the slope in the equation y=2x + 3?
a)
2
b)
3
c)
5
d)
Cannot be Determined 
8.
What is the y-intercept in the equation y= -2x + 5
a)
-2
b)
3
c)
5
d)
Cannot be Determined
9.
What is the slope in the equation y=2x + 3?
a)
2
b)
3
c)
5
d)
Cannot be Determined 
10.
If m=3 and b=6, what is the correct slope intercept equation?
a)
y=3-6
b)
y=3x-6
c)
y=3x+6
d)
y=6x+3
Answer Key

write the equation of a line from a graph

Total questions: 10

1.
b) m
2.
c) y-intercept
3.
d) y = -1/2x + 2
4.
b) y = 1/3x - 2
5.
c) y = -4/5x + 3
6.
a) Zero
7.
a) 2
8.
c) 5
9.
a) 2
10.
c) y=3x+6

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FAQs

What does this worksheet cover, and how does it help students write equations from graphs?

This Grade 8 worksheet focuses on connecting graphs to slope-intercept form, y = mx + b. Its 10 multiple-choice items ask students to identify m as slope and b as y-intercept, read slope and intercept information, classify slope, match graphed lines to equations, and build an equation when m and b are given.

How can I use this worksheet to teach writing a line equation from a graph?

First model how to read the y-intercept and determine the slope from a graphed line, then show how to place those values into y = mx + b. Have students explain why a graph with a zero slope differs from lines with positive, negative, or fractional slopes before completing the matching and equation-selection items on this worksheet.

What mistakes should I watch for when students complete this slope-intercept worksheet?

Watch for students choosing the constant term as the slope, since several items require them to distinguish m from b. Students may also reverse the sign of a slope, confuse a fractional slope such as -4/5 with its reciprocal, or omit the x when forming an equation from given values of m and b.

How do I assign and grade this line-equation worksheet?

You can assign this worksheet as a printable PDF or use it as a digital quiz on Wayground. The complete answer key supports quick grading, and printable student work can be scanned and graded with the Wayground for Teachers app.

How can I differentiate this worksheet for students who need support with slope-intercept form?

Under the worksheet’s Advanced Settings, adjust font spacing or choose a larger font size so the equation choices and graph-based prompts are easier to read. You can also apply a dyslexia-friendly font or translate the worksheet into another language when appropriate for your learners.

Where can I find more free worksheets like this on Wayground?

Wayground offers a broad collection of free printable worksheets and practice problems across subjects, with downloadable PDFs and answer keys to support essential skills and concepts. Browse more resources at https://wayground.com/en-us/worksheets.

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