SOLUTION: what is the equation of a line given the two points (2,1) (-2,-1)

Question 626970: what is the equation of a line given the two points (2,1) (-2,-1)
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!

First let's find the slope of the line through the points

and

Note:

is the first point

. So this means that and .
Also,

is the second point

. So this means that and .

Start with the slope formula.

Plug in , , , and

Subtract from to get

Subtract from to get

Reduce

So the slope of the line that goes through the points

and

is

Now let's use the point slope formula:

Start with the point slope formula

Plug in , , and

Distribute

Multiply

Add 1 to both sides.

Combine like terms.

Remove the trailing zero

So the equation that goes through the points

and

is

Notice how the graph of goes through the points

and

. So this visually verifies our answer.
Graph of through the points

and

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