Graph Skills: Unit Four

Detailed Answers to Additional Practice: The Slope and
y-intercept in the Equation of a Line

What are the slopes and y-intercepts of the following equations?
The equation of a straight line has the form:

1. y = 5 x + 1 Slope = 5 y-intercept = 1

In this question, the constant that multiplies the x variable is 5, therefore this is the slope. The constant that you get when x = 0 is 1, therefore the y-intercept is 1.

2. y = x Slope = 1 y-intercept = 0

In this question, the constant that multiplies the x variable is 1, therefore this is the slope. The constant that you get when x = 0 is 0, therefore the y-intercept is 0.

3. y = 21 - 3 x Slope = -3 y-intercept = 21

In this question, the constant that multiplies the x variable is 3, therefore this is the slope. The constant that you get when x = 0 is 21, therefore the y-intercept is 21.

4. y = - 30 x + 2 Slope = -30 y-intercept = 2

In this question, the constant that multiplies the x variable is -30, therefore this is the slope. The constant that you get when x = 0 is 2, therefore the y-intercept is 2.

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1. y = 5 x + 1	Slope = 5	y-intercept = 1
	In this question, the constant that multiplies the x variable is 5, therefore this is the slope. The constant that you get when x = 0 is 1, therefore the y-intercept is 1.
2. y = x	Slope = 1	y-intercept = 0
	In this question, the constant that multiplies the x variable is 1, therefore this is the slope. The constant that you get when x = 0 is 0, therefore the y-intercept is 0.
3. y = 21 - 3 x	Slope = -3	y-intercept = 21
	In this question, the constant that multiplies the x variable is 3, therefore this is the slope. The constant that you get when x = 0 is 21, therefore the y-intercept is 21.
4. y = - 30 x + 2	Slope = -30	y-intercept = 2
	In this question, the constant that multiplies the x variable is -30, therefore this is the slope. The constant that you get when x = 0 is 2, therefore the y-intercept is 2.