How do you graph #-3x-9y=-18# using intercepts?

1 Answer
Jan 18, 2017

Answer:

#"plot " (0,2),(6,0)#

Explanation:

We can simplify the equation by multiplying through by - 1

#rArr3x+9y=18#

To find the x-intercept substitute y = 0 into the equation and solve for x

#3x+(9xx0)=18rArr3x=18rArrx=6#

#rArrx=6larr" is the x-intercept"#

To find the y-intercept substitute x = 0 into the equation and solve for y

#(3xx0)+9y=18rArr9y=18rArry=2#

#rArry=2" is the y-intercept"#

Plot the points (0 ,2) and (6 ,0), draw a straight line through them and you have the graph.
graph{-1/3x+2 [-10, 10, -5, 5]}