How to find the equation of a line which is passing through two points

Question:-

Find the equation of line passing through the points(-1,7)and (0,15)

Answer:-

Step 1:-

finding the slope of line = m

                      y2-y1     15-7         8
Formula to find slope ------- = ------- = ------ = 8
                      x2-x1     0-(-1)      0+1

so ,slope of a line is 8

step 2:-

The point slope form of equation (y-y1)=m(x-x1)

We know that (x1,y1) is (-1,7)

and m=8

So (y-7)=m-(x-(-1))

(y-7)=8(x+1)

y-7=8x+8
+7   +7
---------
y=8x+15

step 3:-

The equation of the line becomes

             y=8x+15

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