How do you write an equation of a line given point (1,-6) and m=-1?

1 Answer
Feb 27, 2017

(y + color(red)(6)) = color(blue)(-1)(x - color(red)(1))(y+6)=1(x1)

Or

y = color(red)(-1)x - color(blue)(5)y=1x5 or y = -x - 5y=x5

Explanation:

We can use the point-slope formula to find this equation. The point-slope formula states: (y - color(red)(y_1)) = color(blue)(m)(x - color(red)(x_1))(yy1)=m(xx1)

Where color(blue)(m)m is the slope and color(red)(((x_1, y_1))) is a point the line passes through.

Substituting the values from the problem gives:

(y - color(red)(-6)) = color(blue)(-1)(x - color(red)(1))

(y + color(red)(6)) = color(blue)(-1)(x - color(red)(1))

Or we can solve for y to put the equation in slope-intercept form. The slope-intercept form of a linear equation is: y = color(red)(m)x + color(blue)(b)

Where color(red)(m) is the slope and color(blue)(b) is the y-intercept value.

y + color(red)(6) = (color(blue)(-1) xx x) - (color(blue)(-1) xx color(red)(1))

y + color(red)(6) = -x + 1

y + color(red)(6) - 6 = -x + 1 - 6

y + 0 = -x - 5

y = color(red)(-1)x - color(blue)(5)