Question

What is the equation of the line that passes through the points (-5,5) and has a slope of -1

Answer 1

Answer (assuming it can be in slope-intercept form):

`y = -x`

Explanation:

1) Use the point-slope formula
`y-y_1 = m (x-x_1)` to write the equation of the line in point-slope form. Substitute
`m`,
`x_1`, and
`y_1` for real values.

Since the
`m` represents the slope, substitute -1 in its place. Since
`x_1` and
`y_1` represent the x and y values of a point the line intersects, use the x and y values of the point (-5,5) for the formula. Substitute -5 for
`x_1` and 5 for
`y_1`.

`y-(5) = -1(x-(-5))\\y-5 = -1(x+5)`

2) From the above equation, isolate y to place the equation in slope-intercept form and find the final answer:

`y-5=-1(x+5)\\y-5 = -x -5\\y = -x + 0\\y = -x`