What is the slope-intercept form of this equation 3x + 9y = 18?

1 Answer
Mar 21, 2017

See the entire solution process below:

Explanation:

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.

Therefore we must solve this equation for #y#:

#3x + 9y = 18#

#-color(red)(3x) + 3x + 9y = -color(red)(3x) + 18#

#0 + 9y = -3x + 18#

#9y = -3x + 18#

#(9y)/color(red)(9) = (-3x + 18)/color(red)(9)#

#(color(red)(cancel(color(black)(9)))y)/cancel(color(red)(9)) = (-3x)/color(red)(9) + (18)/color(red)(9)#

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