Function:
As we can see, this is a linear function (the exponent of the variables equals 1). Therefore, to graph it, it is easier to have it in the slope-intercept form:
where m represents the slope and b the y-intercept.
To get this form, we have to isolate the y variable by subtracting (-2x) from both sides of the equation:
Simplifying we get:
Now that we have the equation, we can get some coordinates to then add them to the plane. Also, based on this form of the equation, we can see that it has a negative slope, and we can get our first coordinate based on the parameter b, which in this case b = 9; meaning that our first coordinate is (0, 9).
Consequently, we can choose a value for x and solve for y.
• x = -4
The coordinate for this is (-4, 17).
• x = -2
The coordinate for this is (-2, 13).
• x = 1
The coordinate for this is (1, 7).
• x = 3
The coordinate for this is (3, 3).
And we can do this as much as we need to to get enough coordinates. At the end, we have to unite those points and that would be our function.
Answer:
• (-4, 17)
,
• (-2, 13)
,
• (1, 7)
,
• (3, 3)