Big Ideas Math: Modeling Real Life, Grade 8
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Big Ideas Math: Modeling Real Life, Grade 8 View details
Chapter Review
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Exercise 34 Page 190

What information can you learn from the slope-intercept form of an equation?

Practice makes perfect
Equations written in slope-intercept form follow a specific format. y= mx+ b In this form, m represents the slope of the line and b represents the y-intercept.

Identifying the Slope and y-intercept

Since the given equation is not in slope-intercept form, let's rewrite it so that it will be easier to identify the slope and y-intercept.
1/4x+y = 3
1/4x+y - 1/4x = 3 -1/4x
y= 3 - 1/4x
y= - 1/4x +3
Below we have highlighted the slope m and y-intercept b. y= - 1/4x+ 3 The slope is - 14x. The y-intercept is 3, so the graph crosses the y-axis at the point (0, 3).

Graphing the Equation

A slope of - 1/4 means that for every 4 units we move in the positive horizontal direction, we move 1 unit in the negative vertical direction. m= - 1/4 ⇔ rise/run=- 1/4 To graph the equation, plot the y-intercept and then use the slope to find another point on the line.