The equation y = 2x + 1 is an example of a linear equation. When plotted on a coordinate plane, the result is a straight line. The generic version of the linear equation is y = mx + b, with m representing the slope of the line and b representing the y intercept, which is the point where the line crosses the y axis.
Make a T chart and fill in some values for x
Make a chart with two columns. Label the left column "x" and the right column "y = 2x + 1." Fill in the left column with values for x such as 4, 2, 0, -2 and -4. Choose any x values.
Calculate a y value for each x value
Plug each x value into the equation y = 2x + 1. For instance, for x = 4, the y value is found by multiplying 4 times 2 and adding 1, resulting in a y value of 9. Fill in the y value for all x values on the T chart. Using the set of x-values 4, 2, 0, -2 and -4, the resulting y values are 9, 5, 1, - 3 and -7, respectively.
Plot the coordinate points
Writing each pair of x and y-values as coordinate points yields the following set of points: (4, 9), (2, 5), (0, 1), (-2, -3) and (-4, -7). Plot these points on the coordinate plane, and draw a line connecting them. The result is a straight line with a slope of 2 that crosses the y axis at the point (0, 1).