What is the equation of a line passing through (6, -3) with a y-intercept of 8?

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In summary, to find an equation of the line passing through (6, -3) and having a y-intercept of 8, we first need to find the slope by using the point-slope formula. Then, we can rearrange the equation in slope-intercept form to get our final answer of y = mx + b.
  • #1
mathdad
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Find an equation of the line passing through (6, -3) and has y-intercept 8. Express final answer in the form y = mx + b.

If it has y-intercept 8, this means the point (0, 8).

I now have 2 points.

1. Find the slope

2. Use the point-slope formula

3. Solve for y

Correct?
 
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  • #2
A line passing through the point:

\(\displaystyle \left(x_1,y_1\right)\)

And having the $y$-intercept $b$, expressed in slope intercept form, will be:

\(\displaystyle y=\frac{y_1-b}{x_1}x+b\)
 
  • #3
Is my information correct?
 
  • #4
RTCNTC said:
Is my information correct?

Essentially, although I would change step 3 to read "Arrange in slope-intercept form." It's not enough to just solve for y, because we could have solved for y but not used the slope-intercept form, such as:

\(\displaystyle y=m(x-a)+b\)

We would want to arrange this as:

\(\displaystyle y=mx+(b-ma)\)
 
  • #5
By solving for y I meant slope-intercept form y = mx + b.
 

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