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The equation of the line through A(3,-2) and B(9,2)

User Ptutt
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Answer:

Step-by-step explanation:Example 1: Find the equation of the line passing through the points (–1, –2) and (2, 7).

Step 1: Find the slope of the line.

To find the slope of the line passing through these two points we need to use the slope

formula:

( )

( )

So the slope of the slope of the line passing through these two points is 3.

Step 2: Use the slope to find the y-intercept.

Now that we know the slope of the line is 3 we can plug the slope into the equation and

we get:

y = 3x + b

Next choose one of the two point to plug in for the values of x and y. It does not matter

which one of the two points you choose because you should get the same answer in either

case. I generally just choose the first point listed so I don’t have to worry about which

one I should choose.

(–1, –2) → –2 = 3(–1) + b Multiply to simplify the problem.

–2 = –3 + b Solve for b and you will have the y-intercept.

b = 1

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