Question 802495
Linear equations, such as {{{y= -2x+7}}} graph as straight lines.
To graph the line, you just need to determine two points and connect them with a straight line.
However, some teachers may insist on having more points.
They may like their work shown in a certain way, maybe with a table of x and y values.
Your stepson may know if the teacher has some special requirements.
It is a good idea to use grid paper, or graph paper.
You can but the paper, or you can download and print some nice graphing papers.
I used to print those for my children (now in college and beyond).
 
I will show you how to calculate a few points, put them on a table, plot the points, and draw the line.
(The teacher may prefer a different style, but I hope this helps.
 
For {{{x=0}}}, {{{y = -2*0+7}}} --> {{{y=0+7}}} --> {{{y=7}}}
That gives you the point (0,7), with {{{x=0}}} and {{{y=7}}}.
(That point and the value for {{{y}}}, {{{7}}} are often called the y-intercept, because it is the point where the line crosses the y-axis).
 
For {{{x=3}}}, {{{y=2*3+7}}} --> {{{y=6+7}}} --> {{{y=13}}}
That gives you the point (3,13), with {{{x=3}}} and {{{y=13}}}.
 
For {{{x=-5}}}, {{{y=2*(-5)}}} --> {{{y=-10+7}}} --> {{{y=-3}}}
That gives you the point (-5,-3), with {{{x=-5}}} and {{{y=-3}}}.
 
A table with just those 3 points would look like this:
{{{matrix(2,4,x,-5,0,3,y,-3,7,13)}}}
(I made the table horizontal with the x values on the top row, and the corresponding y value below each x value. The teacher may want the table vertical with the x values on the left column, and the y values in another column, each y to the right of the corresponding x).
 
The graph would look like this:
{{{drawing(300,300,-10,10,-6,14,
grid(1),blue(circle(-5,-3,0.4)),
blue(circle(0,7,0.4)),blue(circle(3,13,0.4)),
blue(line(-10,-13,10,27))
)}}}
 
NOTES:
I made rather big circles around the points (-5,3), (0,7), and (3,13) to make them more visible.
The teacher may like less obvious markings or no visible marking at all.
Not having graph paper, or grid paper, I drew a grid the best way I could do it. Unfortunately, my grid lines do not go through the points calculated, but if I were the teacher, this would be an acceptable graph.