Reading slope-intercept form
In y = mx + b, m is the slope and b is where the line crosses the y-axis.
The common mistake
Reading the slope before the equation is solved for y, e.g. saying 2y = 6x + 4 has slope 6.
Instead: Get y alone first (divide every term), then read m and b.
Worked example with Guide me
Find the slope and y-intercept of 2y = 6x + 4.
- Sugar · Is y alone yet?Student · No, it's 2y.
- Sugar · Divide every term by 2.Student · y = 3x + 2.
- Sugar · Now read m and b.Student · Slope 3, crosses at (0, 2).
Answer: m = 3, b = 2
Try 3 practice questions
1. Slope and intercept of y = −4x + 7?
Show answer
m = −4, b = 7
2. Slope and intercept of 3y = 9x − 6?
Show answer
m = 3, b = −2
3. Slope and intercept of y − 5 = 2x?
Show answer
m = 2, b = 5
Quick answers
- What is the most common mistake with reading slope-intercept form?
- Reading the slope before the equation is solved for y, e.g. saying 2y = 6x + 4 has slope 6.
- How do I get reading slope-intercept form right?
- Get y alone first (divide every term), then read m and b.
- Can you show a worked example?
- Find the slope and y-intercept of 2y = 6x + 4. m = 3, b = 2
Related concepts
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