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What is the equation for the line in slope-intercept form?

What is the equation for the line in slope-intercept form?-example-1
User Qubit
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1 Answer

10 votes
10 votes

Answer:

y = -2x - 4

Explanation:

Slope intercept form : y = mx + b

Where

  • m = slope
  • b = y intercept

Finding Y - Intercept

The y intercept is the point where the line crosses the y axis.

Here, just by looking at the graph we can say that the y intercept is at (0,-4) because that is where the line passes the y intercept.

This means that b = - 4

Finding the slope

We can find the slope using the following formula

Slope = (y2-y1)/(x2-x1)

Where, (x1,y1) and (x2,y2) are any given points on the line

The points used can vary however I have chosen (0,-4) and (-2,0)

Defining our variables we get (x1,y1) = (0,-4) and (x2,y2) = (-2,0)

So we have x1 = 0 , x2 = -2 , y1 = -4 and y2 = 0

We now plug this in to the formula

Slope = (y2-y1)/(x2-x1)

==> plug in x1 = 0 , x2 = -2 , y1 = -4 and y2 = 0

Slope = (0-(-4))/(-2-0)

==> remove parenthesis

Slope = (0+4)/(-2-0)

==> simplify addition and subtraction

Slope = 4/-2

==> simplify fraction

Slope = -2

So the slope or "m" is -2

Plugging the y intercept and slope into y intercept form

Again we have y = mx + b

m = slope so m = -2 and b = y intercept so b = -4

Plugging this in, we acquire y = -2x - 4

User Rajneesh
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