Question 15091: I am having trouble finding how to write the equation with certain given points..
Please help me
The questions are:
Write the equation of the line with slope m=4 that passes through the point (2,1).
Write the equation of the through (4,-3) with the slope m=-2/3.
Write the equation of a line that passes through the points(5,4) and (6,9).
Write the equation of a line that passes through the points (-7,-4) and (3,-5)
Write the equation of the line through (-2,0) and (0,3)
Please help me figure out how to do these, I am stuck and truely need your help asap.
Thanks MelMel
Found 2 solutions by bam878s, Earlsdon:
Answer by bam878s(77)   (Show Source):
You can put this solution on YOUR website! to find the equation of a line through a point we need to know the point-slope formula for a line.
Given slope = m and a point (x1,y1) the equation of a line through this point is
(y-y1) = m(x-x1)
To illustrate: m = 4 and (x1,y1) = (2,1)
(y-1) = 4(x-2) add 1 to both sides
y = 4(x-2) + 1
Y = 4x - 8 + 1
y = 4x - 7 is the equation. I think you can get the rest from here. Just follow the example. Let me know if you need further help
Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website! So many question...and so little time!
I'll help you with #1 and # 3, then you can use these as models for the others.
#1. The equation of the line with slope m = 4 that passes through the point (2, 1)
Since you don't specify the form of the equation, I'll use the slope-intercept form: y = mx + b.
Substitute m = 4 to get:
y = 4x + b Now you substitute the x and y from the given point (2, 1) and solve for b:
1 = 4(2) + b
1 = 8 + b Subtract 8 from both sides.
-7 = b
The final equation is:
y = 4x - 7
#3. Write the equation of the line that passes through the points (5, 4) and (6, 9)
Again, use the slope-intercept form: y = mx + b
First calculate the slope from:  where:
(x1, y1) = (5, 4) and (x2, y2) = (6, 9)
 Substitute this into the equation: y = mx + b
y = 5x + b Now substitute either (x1, y1) or (x2, y2) from the given points into the equation and solve for b. Let's use (6, 9)
9 = 5(6) + b
9 = 30 + b Subtract 30 from both sides.
-21 = b
The final equation is:
y = 5x - 21
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