What is the equation of the line that has slope 2/3 and passes through the point (-2,1)?

1 Answer
Dec 26, 2016

#(y - 1) = 2/3(x + 2)#

or

#y = 2/3x + 7/3#

Explanation:

To find this equation we can use the point-slope formula:

The point-slope formula states: #(y - color(red)(y_1)) = color(blue)(m)(x - color(red)(x_1))#
Where #color(blue)(m)# is the slope and #color(red)(((x_1, y_1)))# is a point the line passes through.

Substituting the information we are given in the problem produces:

#(y - color(red)(1)) = color(blue)(2/3)(x - color(red)(-2))#

#(y - color(red)(1)) = color(blue)(2/3)(x + color(red)(2))#

To put this into slope-intercept form (#y = mx + b#) we can solve for #y# as follows:

#(y - color(red)(1)) = color(blue)(2/3)x + (color(blue)(2/3) xx color(red)(2))#

#y - color(red)(1) = color(blue)(2/3)x + 4/3#

#y - color(red)(1) + color(green)(1) = color(blue)(2/3)x + 4/3 + color(green)(1)#

#y - 0 = color(blue)(2/3)x + 4/3 + (color(green)(1) xx 3/3)#

#y = color(blue)(2/3)x + 4/3 + color(green)(3/3)#

#y = color(blue)(2/3)x + 7/3#