Graphing Lines from Standard Form of a Linear Equation
1. Find the x and y intercepts.
Example:
The algebraic reason that the
cover up method works.
2x - 3y = 12
x –intercept
Cover up the y term and solve the remaining equation.
2x - 3y = 12
Substitute zero for y and solve.
Solve
2x = 12
x=6
y –intercept
Cover up the x term and solve the remaining equation.
2x - 3y = 12
Solve
-3y = 12
y = -4
2. Graph the x and y
intercepts as points
x –intercept (6, 0)
The x-intercept occurs when the y value
is zero.
2x - 3y = 12
2x – 3(0) = 12
2x = 12
x=6
y –intercept (0, -4)
The y-intercept occurs when the x value
is zero.
Substitute zero for x and solve.
2x - 3y = 12
2(0) – 3y = 12
-3y = 12
y = -4
3. Draw the line through
the intercepts.