Writing an Equation from the y-intercept and Another Point
Grade 8 math students learn to write linear equations in slope-intercept form y = mx + b when given the y-intercept and another point. They calculate slope using the slope formula and identify the y-intercept from the point where x equals zero. Covered in Big Ideas Math, Course 3, Chapter 4: Graphing and Writing Linear Equations.
Key Concepts
To write an equation in slope intercept form, $y = mx + b$, given the y intercept and another point: 1. Use the two points $(x 1, y 1)$ and $(x 2, y 2)$ to calculate the slope: $$m = \frac{{y 2 y 1}}{{x 2 x 1}}$$ 2. Identify the y intercept, $b$, from the point $(0, b)$. 3. Substitute the values for $m$ and $b$ into the equation $y = mx + b$.
Common Questions
How do you write an equation from the y-intercept and another point?
Calculate the slope using m = (y2-y1)/(x2-x1). Identify the y-intercept b from the point where x=0. Then substitute m and b into y = mx + b.
What is slope-intercept form?
Slope-intercept form is y = mx + b, where m is the slope (rate of change) and b is the y-intercept (the value of y when x equals zero).
How do you find slope from two points?
Use the slope formula m = (y2-y1)/(x2-x1). Subtract the y-values and divide by the difference of the x-values. The result tells how steep the line is.
Which textbook covers writing linear equations from points for Grade 8?
This topic is in Big Ideas Math, Course 3, Chapter 4: Graphing and Writing Linear Equations.
What grade level covers writing linear equations?
Writing linear equations in slope-intercept form is typically covered in Grade 8 math.