SOLUTION: Hi everyone, I have had some trouble with the following graphing problem. If someone could show me how to do it I would be really grateful. I need to Find the y-intercept of the

Algebra ->  Graphs -> SOLUTION: Hi everyone, I have had some trouble with the following graphing problem. If someone could show me how to do it I would be really grateful. I need to Find the y-intercept of the       Log On


   



Question 204312: Hi everyone, I have had some trouble with the following graphing problem.
If someone could show me how to do it I would be really grateful.
I need to Find the y-intercept of the straight line passing through points (-3,1) and (-1,-2).
I really want to learn how to solve these types of equations, so steps and explanations would be nice.
Thnaks, -Nick.

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the y-intercept of the straight line passing through points
(-3,1) and (-1,-2)
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First you have to find the slope:
slope = (-2-1)/(-1--3) = -3/2
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Then you use the form y = mx + b to find b, which is the y-intercept.
You know y = 1 when x = -3 and you know m = -3/2
So solve for "b":
1 = (-3/2)-3 + b
1 = 9/2 + b
b = -7/2
The y-intercept is -7/2 or (0,-7/2).
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graph%28400%2C300%2C-10%2C10%2C-10%2C10%2C%28-3%2F2%29x-%287%2F2%29%29
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Cheers,
Stan H.