Question

Which of the following point-slope form equations could be produced with the points (-1, -2) and (4, -3)?

Answer 1

y+2 = -1/5(x+1) or y+3 = -1/5(x-4)

Explanation:

Point-slope form is given by the equation

y-y1 = m(x-x1)

Given two points, you can calculate m (the gradient) using the formula
`(y2-y1)/(x2-x1)`

In this case, m is
`(-3 - (-2) )/(4 - (-1))`

m = -1/5

There are now two options for the point-slope form, as we have two points. In both cases, the y co-ordinates can be subbed in placed of the y1, and the x co-ordinates in place of the x1.

Therefore the two possible solutions are:

y - (-2) = -1/5(x - (-1))

Which simplifies to y+2=-1/5(x+1)
Or

y - (-3) = -1/5(x-4)

Which simplifies to y+3 = -1/5(x-4)

Hope that helps!