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Question 919040: find the slope of the line containing the pair of points
(-5,-10) and (-4,-3)
Found 2 solutions by Alan3354, MathLover1:
Answer by Alan3354(69443)   (Show Source):
Answer by MathLover1(20849)  (Show Source):
You can put this solution on YOUR website!
now we can use a slope and one point to find equation of a line:
| Solved by pluggable solver: FIND a line by slope and one point |
What we know about the line whose equation we are trying to find out:
- it goes through point (-5, -10)
- it has a slope of 7
First, let's draw a diagram of the coordinate system with point (-5, -10) plotted with a little blue dot:
Write this down: the formula for the equation, given point  and intercept a, is
 (see a paragraph below explaining why this formula is correct)
Given that a=7, and  , we have the equation of the line:
Explanation: Why did we use formula  ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point ( ,  ) lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (, ):  Here, we know a, , and , and do not know b. It is easy to find out:  . So, then, the equation of the line is:  .
Here's the graph:
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here is better picture of a graph:
(-4,-3)
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