Graphing equations.

[Jonathan Dolen]

Hi all. I have some questions, about graphing equations.


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1. Write the equation of a line with an x-intercept of 1 and a slope of 3.

2. Write the equation of a line with the slopeof -4 and a y-intercept of 3.

3. What is true about the slope of two parallel lines?

4. Write the equation of the line with the slope of 8 passing through the point (4, 1).

5. Write the equation of the line with the points (-2, -5) and (6, -5)

Thank you.

 

[~Midnight.Kitten~]

yeah that stuff is confusing..

 

[Guest]

1. Write the equation of a line with an x-intercept of 1 and a slope of 3.

The x-intercept is the value of x when y = 0, so to have an x-intercept of 1 is to pass through the point (1, 0). You have a point and the slope, so you can use the point-slope formula:

. . . . y - y₀ = m(x - x₀)

where m is the slope of the line and (x₀, y₀) is a point on the line.

2. Write the equation of a line with the slopeof -4 and a y-intercept of 3.

The equation y = mx + b has slope m and y-intercept b. Plug 'em in.

3. What is true about the slope of two parallel lines?

Parallel lines are defined as lines with the same slope.

4. Write the equation of the line with the slope of 8 passing through the point (4, 1).

You can use the point-slope formula here, just like in number 1.

5. Write the equation of the line with the points (-2, -5) and (6, -5)

First, find the slope. The slope is change in y divided by change in x:

. . . . m = (y₁ - y₀) / (x₁ - x₀)

Then pick a point and use the point-slope formula.