Question

Find the equation (in terms of x) of the line through the points (-2,1) and (3,5)

Answer 1

9514 1404 393

Answer:

  y = 4/5x +13/5

Step-by-step explanation:

The slope is given by the formula ...

  m = (y2 -y1)/(x2 -x1)

  m = (5 -1)/(3 -(-2)) = 4/5

The y-intercept is given by the formula ...

  b = y -mx . . . . for any point (x, y)

  b = 1 -(4/5)(-2) = 1 +8/5 = 13/5 . . . . using the first point

So, the equation is ...

  y = mx +b

  y = 4/5x +13/5

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Additional comment

If you have a bunch of these to do, you may want to make a spreadsheet with the formulas built in. Then you can type in the two points and have it spit out the m and b for your equation. Even if you don't use it to do the work, you can use it to check the work.