AlgebraLab

Algebra II Recipe: Quick Graphs of Linear Equations

By G Redden

A. Using Slope-Intercept Form
  1. Slope-Intercept form is y = mx + b
    • "m" represents the slope.
    • "b" represents the y-intercept.
  2. Steps for graphing using y = mx + b
    • Solve the equation for y.
    • Determine the slope and y-intercept.
    • Graph the y-intercept.
    • Use the movements from slope (or rise/run) to graph more points from the y-intercept.
    • Connect the points with a straight line and arrows on each end.
    • Label the line with its equation.
1.
y = ¾x - 2
2.
8x - 2y = 14
B. Using x and y Intercepts to Graph.
  1. x-intercept - the point where the line crosses the x-axis.
  2. y-intercept - the point where the line crosses the y-axis.
  3. Find the x-intercept.
    • Substitute zero in place of y in the equation.
    • Solve the equation for x.
    • You get the ordered pair (x, 0).
  4. Find the y-intercept.
    • Substitute zero in place of x in the equation.
    • Solve the equation for y.
    • You get the ordered pair (0, y).
  5. Graph the two intercepts or points.
    • Connect the points with a straight line and arrows on each end.
    • Label the line with its equation.
3.
2x + 3y = 12
4.
2x - 5y = 10