How do you graph the equation #3x+7y=42#?

1 Answer
Mar 30, 2018

graph{3x+7y=42 [-10, 10, -5, 5]}


#7y=-2x+42# isolate y-term to put into slope-intercept form #y=mx+b#
#y=-2/7x + 6# divide by 7 to isolate y
Plot first point: (0,6). This is given by the equation, where #b=6#. This is your y-intercept, or where x equals 0 and the line crosses the y-axis.
Next, you want to use the slope to get your next point. Remember: the slope is rise over run. In other words, because your slope is #-2/7#, you want to RISE -2 (because this is a negative number, you will go down 2), and RUN 7 (because this is a positive number, you will go 7 to the right). Plot this point and connect the two points to give you your line.