How do you write an equation of a line with point (-4,6), slope -2?

1 Answer
Jun 25, 2018

See a solution process below:

Explanation:

We can use the point-slope formula to write an equation for this line. The point-slope form of a linear equation is: #(y - color(blue)(y_1)) = color(red)(m)(x - color(blue)(x_1))#

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

Substituting the values from the point in the problem and the slope from the problem gives:

#(y - color(blue)(6)) = color(red)(-2)(x - color(blue)(-4))#

#(y - color(blue)(6)) = color(red)(-2)(x + color(blue)(4))#

We can also 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(blue)(6) = (color(red)(-2) xx x) + (color(red)(-2) xx color(blue)(4))#

#y - color(blue)(6) = color(red)(-2)x + (-8)#

#y - color(blue)(6) = color(red)(-2)x - 8#

#y - color(blue)(6) + color(blue)(6) = color(red)(-2)x - 8 + color(blue)(6)#

#y - 0 = color(red)(-2)x - color(blue)(2)#

#y = color(red)(-2)x - color(blue)(2)#