Find the equation of the line that goes through the points (-15, 70) and (5,10)

Question

anonymous · Answer

Solve for slope first using: y2-y1/x2-x1 to get: 70-10/5 -(-15) = 60/20 = 3

Plug that into: y = mx + b.

Now, you have y = 3x + b. Use any of the ordered pairs you have to substitute into the equation. 

For instance, you use, (5,10) where x = 5 and y = 10 to get: 

                      10 = 3(5) + b = 0
                      10 = 15 + b            
                      -5 = b                                      *Note: subtract 15 from both sides 

So, now you have: y = 3x - 5